Answer: 65 grams
Step-by-step explanation:
If 130 grams of a gold alloy (a mixture of gold and one or more other metals) containing 85% pure gold, you should first calculate the amount of gold that makes up this percentage.
That is, 85% of 130 grams.
85/100 × 130 = 110.5
Then, let X be what will be added to the above value to make 90%. So,
(110.5 + X) / ( 130 + X ) × 100 = 90
Divide both sides by 100
(110.5 + X) / ( 130 + X ) = 90/100
(110.5 + X) / ( 130 + X ) = 0.9
Cross multiply and open the bracket
110.5 + X = 117 + 0.9X
Collect the like terms
X - 0.9X = 117 - 110.5
0.1X = 6.5
Divide both sides by 0.1
X = 6.5/0.1
X = 65 grams
Therefore, the amount of pure gold that should be added is 65 grams
Explain how you can determine that the following system has one unique solution – without actually solving the system.
2x+y=4
2y=6-2x
Answer:
Step-by-step explanation:
Well, first you'd have to get the equations in slope-intercept form in order to make it easier for you to see it in the bigger picture. 2x+y=4 would be y= 2x-4, and the other equation would be y= x-3. If you were to solve it, there would be one solution since the y's cancel out. If you graphed it, there would be a point of intersection, unlike when the lines are parallel if there's 0 solutions or only one line's there if there's infinitely many solutions.
salem had to withdraw 28.50 from his bank account every week for 5 weeks to pay a purchase. what number represents a change in his bank account
Answer:
Okay so he had to withdraw 28.50 from his bank account every week so that means he withdrew 142.5 that in 5 weeks
Step-by-step explanation:
con
Simplify: -165 - 1703
Answer:
[tex]-1868[/tex]
Step-by-step explanation:
[tex]-165 - 1703[/tex]
Subtract the numbers.
[tex]=-1868[/tex]
Answer:
-1868 is the simplified polynomial
Step-by-step explanation:
-165 -1703
= -165 + -1703
= -(165+1703)
= -(1868)
If the measure of angle 3 is equal to (2x + 6) and x = 7, which statements are true?
Check all that apply .
Answer:The measure of angle 6 is 20. The measure of angle 5 is 70. Angles 2 and 5 are complementary. Angles 1 and 4 are supplementary.
Step-by-step explanation:
What is the measure of Zx?
Angles are not necessarily drawn to scale.
P
R
36
29
S
2=
Answer:
x=54 degrees
Step-by-step explanation:
These two angles are complementary, meaning that they add to 90 degrees.
If one angle is 36 degrees, then we can write this equation: 36+x=90
We want to find what x is, so we should isolate x.
We can isolate x by subtracting 36 on both sides.
x=90-36
x=54
Answer:
54°
Step-by-step explanation:
∠PQR +∠RQS =∠PQS
36° + x° = 90°
x = 90 - 36 = 54°
Add the following polynomials, then place the answer in the proper location on the grid. Write your answer in descending powers of x. x4 -3x + 1, 4x2 - 2x + 8, and x3 - 9
Answer:
x⁴ + x³ + 4x² - 5x
Step-by-step explanation:
The polynomials given in the question are:
x⁴ - 3x + 1
4x² - 2x + 8
x³ - 9
We have to add all them
First write all the polynomial in the summation form:
(x⁴ - 3x + 1) + (4x² - 2x + 8) + (x³ - 9)
Open the brackets:
x⁴ - 3x + 1 + 4x² - 2x + 8 + x³ - 9
Group together the similar terms
(x⁴) + (x³) + (4x²) + (-3x -2x) + (1 + 8 - 9)
Finding the sum in brackets:
x⁴ + x³ + 4x² + (-5x) + (0)
x⁴ + x³ + 4x² - 5x
Note that the sum is in descending powers of x
Which of the following pairs of functions are inverses of each other? A)f(x)=2x-9 and g(x)=(x+9)/(2) B)f(x)=(2)/(x)-6 and g(x)=(x+6)/(2) C)f(x)=(x)/(3)+4 and g(x)=3x-4 D)(x)=5+\root(3)(x) and g(x)=5-x^(3)
Answer:
A)f(x)=2x-9 and g(x)=(x+9)/(2)
Step-by-step explanation:
f(g(x)) =x for inverses
A)f(x)=2x-9 and g(x)=(x+9)/(2)
2(x+9)/2) -9 = Canceling the 2 x+9 -9 = x inverse
B)f(x)=(2)/(x)-6 and g(x)=(x+6)/(2)
2/(x+6)/2 ) -6 =4/(x+6) - 6 This will not give me x
C)f(x)=(x)/(3)+4 and g(x)=3x-4
(3x+4)/3 -4 = x + 4/3 -4 This will not give me x
D)(x)=5+\root(3)(x) and g(x)=5-x^(3)
5 + cuberoot ( 5-x^3) This will not give me x back
Answer:
2x-9 is the inverse of x+9/2
Step-by-step explanation:
HELP ME PLEASE REALLY IMPORTANT OR ILL GET IN TROUBLE!! WILL MARK AS BRAINLEST IF YOU GET IT CORRECT!!
Answer: C, It stays the same.
Step-by-step explanation: If you simplify the ratio (the fraction) by canceling the t's, you get 2/1 or 2:1. This means that no matter the value of the variable t, the value of the expression will stay the same.
Can you help me please.
Step-by-step explanation:
[tex]a) \\ (8 \times {10}^{ - 3} ) \times (2 \times {10}^{ - 4} ) \\ = 8 \times 2 \times {10}^{ - 3} \times {10}^{ - 4} \\ = 16 \times {10}^{ - 3 - 4} \\ = 16 \times {10}^{ - 7} \\ = 1.6 \times {10}^{ - 6} \\ \\ b) \\ (6 \times {10}^{ 2} ) \div (3\times {10}^{ - 5} ) \\ \\ = \frac{6 \times {10}^{ 2}}{3\times {10}^{ - 5}} \\ \\ = \frac{2\times {10}^{ 2}}{ {10}^{ - 5}} \\ \\ = 2 \times {10}^{ 2 + 5} \\ \\ = 2 \times {10}^{7} \\ [/tex]
What is the permeter of square ABCD?
Answer:
24.3 units (3 s.f.)
Step-by-step explanation:
Since a square has 4 equal sides,
perimeter of ABCD= 4(length of AB)
Distance between 2 points
=[tex] \sqrt{(y1 - y2)^{2} + (x1 - x2)^{2} } [/tex]
Length of AB
[tex] = \sqrt{( { - 2 - 4)}^{2} + {(2 - 3)}^{2} } \\ = \sqrt{( - 6)^{2} + ( - 1)^{2} } \\ = \sqrt{37} [/tex]
perimeter of ABCD
[tex] = 4 \sqrt{37} \\ = 24.3 \: units \: (3 \: s.f.)[/tex]
Which elements in the same below are integers? -3,3.7,9,-7.34,2.83,5,56/7,-1
Answer:
Integers -3, 9, 5, 56/7, -1
Step-by-step explanation:
Integers are whole numbers that can be positive or negative. They do not have decimals.
4.3cm round to 3 decimal places?
Answer:
0.4
Step-by-step explanation:
Find the size of the final unknown exterior angle in a polygon whose other exterior angles are:
63', 64°, 82°, 49° and 58°
Answer: 44°
Step-by-step explanation:
The sum of the exterior angles of a polygon is 360°
If your polygon has six sides, the final angle will be:
= 360 - (63 + 64 + 82 + 49 + 58)
= 360 - 316
= 44°
Delaware was the first state to enter the Union and Hawaii was the 50th. If we order the positions of entry for the rest of the states, we find that State A entered the Union right after State B, and the product of their order-of-entry numbers is 132. Use the given information to complete each statement. State A was the th state to enter the Union. State B was the th state to enter the Union.
Answer:
State A was the 12th state to enter the Union. State B was the 11th state to enter the Union.
Step-by-step explanation:
Let's call x to the order-of-entry of State B, therefore the order-of-entry of State A is x+1. Given that he product of their order-of-entry numbers is 132:
x*(x+1) = 132
x² + x - 132 = 0
Using quadratic formula:
[tex]x = \frac{-b \pm \sqrt{b^2 -4(a)(c)}}{2(a)} [/tex]
[tex]x = \frac{-1 \pm \sqrt{1^2 -4(1)(-132)}}{2(1)} [/tex]
[tex]x = \frac{-1 \pm 23}{2} [/tex]
[tex]x_1 = \frac{-1 + 23}{2} [/tex]
[tex]x_1 = 11 [/tex]
[tex]x_2 = \frac{-1 - 23}{2} [/tex]
[tex]x_2 = -12[/tex]
The negative solution has no sense in the context of our problem, then the solution is x = 11.
help me with right answer plz
Answer:
13.5
Step-by-step explanation:
area: 1/2*[x1(y2 - y3) + x2(y3 - y1) + x3(y1 - y2)]
Which table represents a direct variation function?
In a football game, the home team scored 1 touchdown and one extra point during every quarter. How many points did the home team have at the end of the game?
Answer:
28 points
Step-by-step explanation:
A touch down is 6 points and an extra point is 1 point
There are 4 quarters
6+1 = 7
4 quarters
4*7 = 28
They scored 28 points
HURRY PLS!!!
which expression is equivalent to 3(b+ c) using only the distributive property?
3bc
3(c+b)
3b+3c
(b+c) • 3
Answer:
3b + 3c
Step-by-step explanation:
hope this helps you
Answer:
3(c+b)
Step-by-step explanation:
3(b+c) is essentially 3 times B+ 3 times c
and 3(c+b) is 3 times c + 3 times B
I need helppppppppppppp
Answer:$140 for the train ride
$84 for the museum
Step-by-step explanation:
28×5
28×3
All the students + you = 28
If not, try 27×5 and 27×3
Answer:
$216 for the Train Ride and visit to the Museum.Step-by-step explanation:
There are two values to find and add together.
o The admission cost for the Museum
o The admission cost for the Train Ride
Let's make some equations.
x=number of people
Museum: 3x=total cost for Museum (m)
Train Ride: 5x=total cost for Train Ride (t)
m+t= total money spent
Now, let's replace the values.
Museum: 3(27)=$81
Train Ride: 5(27)=$135
$81+$135=$216 for the Train Ride and visit to the Museum.
Hope this helps!
-Emma
Assume that when adults with smartphones are randomly selected, 49% use them in meetings or classes. If 30 adult smartphone users are randomly selected, find the probability that exactly 23 of them use their smartphones
Answer: 0.0013684
Step-by-step explanation:
Given the following :
Probability (p) = 49% = 0.49
Number of selected adults (n) = 30
Find the probability that exactly 23 use their smartphone.
The problem is abive can be solved using the binomial probability function.
Binomial probability :
P(X = x) = [n! / x! (n-x)!] * P^x * (1 - P)^(n-x)
At x = 23
P(X = 23) = [30! / 23! (30-23)!] * P^23 * (1-0.49)^(30-23)
P(X = 23) = [30! / 23! (7)!] * 0.49^23 * (0.51)^7
P(X =23) = (2035800) × 6.72203E−10
= 0.0013684
Which transformations could be performed to show that
AABC is similar to AA"B"C"?
Answer:
add a picture
Step-by-step explanation:
A social scientist surveyed a random sample of male musicians at a university about their practice habits. The graph below displays the amount of time typically spent practicing their instrument daily.
Which of the following inferences can be made from the data?
Answer:
C
Step-by-step explanation:
male musicians practice an avg 2/hrs a day
The inferences can be made from the data on average, male musicians practice for two hours per day. Then the correct option is C.
What is a histogram?A diagram is made up of rectangles whose size is related to a variable's frequency and whose width is comparable to the training sample.
A social scientist surveyed a random sample of male musicians at a university about their practice habits.
The graph below displays the amount of time typically spent practicing their instrument daily.
From the graph, we can conclude that on average, male musicians practice for two hours per day.
Then the correct option is C.
More about the histogram link is given below.
https://brainly.com/question/16819077
#SPJ2
What is the point-slope form of a line with slope -3 that contains the point (10,-1)?
A. y + 1 = 3(x+10)
B. y + 1 = 3(x-10)
C. y + 1 =-3(x-10)
D. x + 1 = -3(y -10)
Answer:
the point slope form is
y + 1= -3(x - 10)
solution is c
John wants to invest in a simple intereset savings account The intereset rate on this account is 0.7%. The account balance y can be modeled by the following linear equation y=150,000+150,000(0.007)x where x represents the time (in years) that john leaves her money in the account what is johns initial investment?
Answer:
John's initial investment is Rs.150000
Step-by-step explanation:
Let the principal amount be a
We are given that John wants to invest in a simple interest savings account .The interest rate on this account is 0.7%.
Now to find simple interest in x years
Formula : [tex]Si = P \times T \times R[/tex]
Where P = Principal
T= time
R = rate of interest in decimals
So,[tex]SI=a \times 0.007 \times x[/tex]
Amount = Principal+Interest
Amount = [tex]a+a(0.007)x[/tex]
We are given that The account balance y can be modeled by the following linear equation y=150,000+150,000(0.007)x
So, On comparing a = 150000
Hence John's initial investment is Rs.150000
Choose the correct simplification of the expression (5x^5)^2 5x^25 10x^10 25x^7 25x^10
Answer:
[tex]25x^{10}[/tex]
Step-by-step explanation:
[tex](5x^5)^2\\\\\text {Apply Rule: }(a*b)^n=a^n b^n\\\\(5x^5)^2=5^2(x^5)^2\\\\25(x^5)^2\\\\\text {Apply rule: } (a^b)^c=a^{bc}\\\\25(x^5)^2=\boxed{25x^{10}}[/tex]
Reagan scored 1140 on the SAT. The distribution of SAT scores in a reference population is normally distributed with mean 1000 and standard deviation 100. Jessie scored 30 on the ACT. The distribution of ACT scores in a reference population is normally distributed with mean 17 and standard deviation 5. Who performed better on the standardized exams and why? Reagan scored higher than Jessie. Reagan's score was 1140, which is greater than Jessie's score of 30. Reagan scored higher than Jessie. Reagan's standardized score was 1.4, which is 1.4 standard deviations above the mean, but closer to the mean than Jessie's standardized score of 2.6 standard deviations above the mean. Reagan scored higher than Jessie. Reagan's score was 140 points above the mean of 1000, and Jessie's was 13 points above the mean of 17. Jessie scored higher than Reagan. Jessie's standardized score was 2.6, which is 2.6 standard deviations above the mean and Reagan's standardized score was 1.4, which is 1.4 standard deviations above the mean. Jessie scored higher than Reagan. Jessie is only 6 points from the top score of 36 on the ACT, and Reagan is 460 points from the top score of 1600 on the SAT.
Answer:
Jessie scored higher than Reagan.
Step-by-step explanation:
We are given that Reagan scored 1140 on the SAT. The distribution of SAT scores in a reference population is normally distributed with mean 1000 and standard deviation 100.
Jessie scored 30 on the ACT. The distribution of ACT scores in a reference population is normally distributed with mean 17 and standard deviation 5.
For finding who performed better on the standardized exams, we have to calculate the z-scores for both people.
1. Finding z-score for Reagan;
Let X = distribution of SAT scores
SO, X ~ Normal([tex]\mu=1000, \sigma^{2}=100^{2}[/tex])
The z-score probability distribution for the normal distribution is given by;
Z = [tex]\frac{X-\mu}{\sigma}[/tex] ~ N(0,1)
where, [tex]\mu[/tex] = population mean = 1000
[tex]\sigma[/tex] = standard deviation = 100
Now, Reagan scored 1140 on the SAT, that is;
z-score = [tex]\frac{1140-1000}{100}[/tex] = 1.4
2. Finding z-score for Jessie;
Let X = distribution of ACT scores
SO, X ~ Normal([tex]\mu=17, \sigma^{2}=5^{2}[/tex])
The z-score probability distribution for the normal distribution is given by;
Z = [tex]\frac{X-\mu}{\sigma}[/tex] ~ N(0,1)
where, [tex]\mu[/tex] = population mean = 17
[tex]\sigma[/tex] = standard deviation = 5
Now, Jessie scored 30 on the ACT, that is;
z-score = [tex]\frac{30-17}{5}[/tex] = 2.6
This means that Jessie scored higher than Reagan because Jessie's standardized score was 2.6, which is 2.6 standard deviations above the mean and Reagan's standardized score was 1.4, which is 1.4 standard deviations above the mean.
whats the answer???
Answer:
a is the answer
have a great day. brainliest please
Step-by-step explanation:
Answer:
the answer is A. :)
Step-by-step explanation:
the answer A. is 10 so just think what 2 times what will equal 10 so....2 x 5 = 10 and we got 10 so that is how we get our answer
Brainliest please thank you! and good luck!
Penny earns $580 more than half of Karen´s salary. If p represents Penny´s salary, write an expression that represents the amount of money Karen earns in relation to Penny.
Answer:
[tex]\frac{p}{2} + $580[/tex]
Step-by-step explanation:
p = Penny's salary
Karen's salary = $580 more than half of p
We can use the fraction [tex]\frac{p}{2}[/tex] to represent half of p.
Since Karen's salary is $580 more, her salary is $580 + [tex]\frac{p}{2}[/tex] .
Answer:
heyyyy
Step-by-step explanation:
Calculate the perimeter of this figure
to the nearest tenth.
P = [? ] ft
Answer: 40.9
Step-by-step explanation:
which of the following equations describe the line shown below? check all that apply. Please Help!
Answer:
A & F
Step-by-step explanation:
if you look at the other question I answered for you, you can see the work. but basically you can figure out slope by doing m=y2-y1/x2-x1.
so we now know the slope is 1/4. which eliminates choices B, D, E.
we see that C will not work because the x and y values are switched.
according to point slope formula A & F work.