Answer:
4pi or 12.57
Step-by-step explanation:
Area = pi * radius^2
Area = pi * 2^2
Area = pi * 4
Area = 4pi or 12.57
Element X is a radioactive isotope such that every 13 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 90 grams, how long would it be until the mass of the sample reached 62 grams, to the nearest tenth of a year?
Answer:
The mass of Element X will reach 62 grams in 7.0 years.
Step-by-step explanation:
We can find the time of decay of Element X by using the exponential decay equation:
[tex] \frac{dm}{dt} = -\lambda t [/tex]
The solution of the above equation is:
[tex]m_{(t)} = m_{0}e^{-\lambda t}[/tex] (1)
Where:
t: is the time =?
λ: is the decay constant
[tex]m_{(t)}[/tex]: is the mass at time t = 62 grams
[tex]m_{0}[/tex]: is the initial mass = 90 grams
First, we need to calculate λ
[tex] \lambda = \frac{ln(2)}{t_{1/2}} [/tex] (2)
Where [tex]t_{1/2}[/tex] is the half-life = 13 years
By entering equation (2) into (1) and solving for "t" we have:
[tex]\frac{m_{(t)}}{m_{0}} = e^{-\frac{ln(2)}{t_{1/2}}*t}[/tex]
[tex]ln(\frac{m_{(t)}}{m_{0}}) = -\frac{ln(2)}{t_{1/2}}*t[/tex]
[tex]t = -ln(\frac{m_{(t)}}{m_{0}})(\frac{t_{1/2}}{ln(2)}) = -ln(\frac{62}{90})(\frac{13}{ln(2)}) = 7.0 y[/tex]
Therefore, the mass of Element X will reach 62 grams in 7.0 years.
I hope it helps you!
hey! i’ll give brainliest help thanks
Answer:
A government by the people
Step-by-step explanation:
What is -11 2/3 x (-4 1/5) = ?
Answer:
49
Step-by-step explanation:
-11 2/3 x (-4 1/5) =
negative times negative = positive
Change the mixed numerals into fractions.
= 35/3 × 21/5
Multiply the numerators together. Multiply the denominators together.
= (35 × 21)/(3 × 5)
Simplify.
= (7 × 5 × 7 × 3)/(3 × 5)
Divide the numerator and denominator by 3 and by 5.
= 7 × 7
= 49
6 = m/8
M=?
What is the answer for M?
Answer:
m =48
Step-by-step explanation:
1st step is to multiply both sides by 8
2nd step it would be 48=m
3rd step swap the sides.. m=48
1.) A butterfly can fly 82 feet in four seconds and a dragonfly can fly 50 feet in two seconds. Which can fly faster and by how much? *
1 point
The dragonfly is 4.5 feet per second faster.
The butterfly is 4.5 feet per second faster.
The dragonfly is 20.5 feet per second faster.
The butterfly is 32 feet per second faster.
Answer:
The dragonfly is 20.5 feet per second faster
Step-by-step explanation:
Answer:
A. The dragonfly is 4.5 feet per second faster.Step-by-step explanation:
Speed of butterfly:
82/4 = 20.5 ft/secSpeed of dragonfly:
50/2 = 25 ft/secThe difference:
25 - 20.5 = 4.5 ft/secCorrect choice is A
In right triangle ABC, a = 7, b = 9 and
Answer: the answer is 63,ABC
Step-by-step explanation:
HELP PLEASE
identify the solution to the system of equations
Answer:
solved graphically,
it's just the point where the two lines intersect
I'll mark the right answer brainliest :)
Answer:
59045
I hope I helped! :)
Please help, thank you!
Answer:
D
Step-by-step explanation:
The very first thing you have to realize is that the temperature goes further down the minus scale which means that only A and D can be correct. That's because time in this question is positive.
So if you just try the first value (x = 3), you will get
-3/2 * 3 = -9/2 which would mean that you would add -4 1/2 onto - 10 which is much larger than - 10
A: is not the answer.
-2/3 * 3 - 10 = -6/3 - 10 = -2 - 10 = - 12
That is the answer you should get. The answer is D.
The table below shows three special sequences (A to C) of numbers.
A 1; 4; 9; 16; 25; 36 ...
B 1:8; 27; 64; 125; 216...
C 1:3; 6; 10; 15; 21; ...
3.1 Write down the next THREE terms of the respective patterns.
3.2.
Identify the pattem (sequence of numbers) represented by each letter.
3.3
Determine the formula for the general term of each sequence.
3.4
Determine the 100 term of each respective pattern.
Answer:
3.1 A) 49; 64; and 81
B) 343; 512; and 729
C) 28; 36; and 45
3.2 A) 1²; 2²; 3²...
B) 1³; 2³; 3³...
C) 1; 1+2; 1+2+3; ...
3.3 A) aₙ = n²
B) aₙ = n³
C) aₙ = n·(n + 1)/2
3.4 A) 10,000
B) 1,000,000
C) 5,050
Step-by-step explanation:
The given sequences are;
A 1; 4; 9; 16; 25; 36...
B 1; 8; 27; 64; 125; 216...
C 1; 3; 6; 10; 15; 21;...
3.1 A) The terms, aₙ, of sequence 'A' are given as follows;
aₙ = n², where, n = 1, 2, 3,...
The next three terms of sequence 'A' are therefore;
a₇ = 7³ = 49, a₈ = 8² = 64, and a₉ = 9² = 81
The next three terms of sequence 'A' are ; 49; 64; and 81
B) The terms, aₙ, of sequence 'B' are given as follows;
aₙ = n³, where, n = 1, 2, 3,...
The next three terms of sequence 'B' are therefore;
a₇ = 7³ = 343, a₈ = 8³ = 512, and a₉ = 9³ = 729
The next three terms of sequence 'B' are; 343; 512; and 729
C) The terms, aₙ, of sequence 'C' are given as follows;
aₙ = n·(n + 1)/2, where, n = 1, 2, 3,...
The next three terms of sequence 'A' are therefore;
a₇ = 7×(7 + 1)/2 = 28, a₈ = 8×(8 + 1)/2 = 36, and a₉ = 36 + 9×(9 + 1)/2 = 45
The next three terms of sequence 'A' are ; 28; 36; and 45
3.2 A) The pattern of the numbers in sequence 'A', consists of squaring (raising to the power of 2) each number in the sequence of natural numbers
B) The pattern of the numbers in sequence 'B', consists of raising to the power of 3 each number in the sequence of natural numbers
C) The pattern is the triangular number sequence and consists of finding half the number dots that are present in a n by (n + 1) rectangle, which is given by finding the sum of the natural numbers up to the given term in the sequence
3.3 A) The formula for the general term of sequence, A, is aₙ = n²
B) The formula for the general term of sequence, B, is aₙ = n³
C) The formula for the general term of sequence, C, is aₙ = n·(n + 1)/2
3.4 A) The 100th term of sequence 'A', a₁₀₀ = 100² = 10,000
B) The 100th term of sequence 'B', a₁₀₀ = 100³ = 1,000,000
C) The 100th term of sequence 'C', a₁₀₀ = 100 × (100 + 1)/2 = 5,050.
Look at the two 2s in this number
Answer: What number?
Step-by-step explanation:
Answer:
In what number... is this a trick question or did you just not finish your question??
Step-by-step explanation:
I need the answer immediately!!!!!!!!
Answer:y=-5x-2
Step-by-step explanation:
This will have a negative slope since the line goes from left to right. Use rise over run to find the slope of -5 and look at the y axis where it intersects to get -2
Have a great day!
Evaluate: 4x(5+3)=8-2
A 2
B 8
C 12
D 15
Answer:
The answer to the problem is 15.
The young mathematician is presented with this problem: (13 + 7) x (5 - 3) / 4 x (1 + 1) = Which operation would the young mathematician do first?
The division
The subtraction
Those inside parentheses
The multiplication
Those inside the parentheses. Rember pemdas or Parentheses Exponets Multiple Divide Add Subtract in that order from left to right
Expand 2x(5x-2)
PLEASEEEEEEEE!!!!!!!!!!!!
Answer:
2x(5x-2) = 10(x^2) - 4x
PLEASE GIVE BRAINLIEST
The Science Club went on a two-day field trip. The first day the members paid $50 for transportation plus
$18 per ticket to the planetarium. The second day they paid $95 for transportation plus $15 per ticket to
the geology museum. Write an expression to represent the total cost for two days for the n members of
the club.
An expression that represents the total cost in dollars for two days for the n members of the club is given
by
HARD! [Ma
Answer:
145 + 33n
Step-by-step explanation:
Let
n = number of members in the club
Day 1:
Cost = 50 + 18n
Day 2:
Cost = 95 + 15n
Total cost two-day field trip = day 1 + day 2
= (50 + 18n) + (95 + 15n)
= 50 + 18n + 95 + 15n
= 145 + 33n
Total cost two-day field trip = 145 + 33n
An expression that represents the total cost in dollars for two days for the n members of the club is given by 145 + 33n
PLS HELP! WILL MARK BRAINLIEST!
Mr. Smith makes a pasta sauce
He mixes tomato concentrate: olive oil at a ratio of 3: 1
How many liters of tomato concentrate does he need to mix if he adds 3 liters of olive oil?
Answer:
9 litres of tomato concentrate
Max drives 85 km at an average speed of 110 km/h and then 7 km at 70 km/h without stopping.
What is the average speed for the whole journey to 1 dp?
Answer:
how much time did it take him???????
Step-by-step explanation:
What is equivalent to 5 to the third power?
Answer:
125
Step-by-step explanation:
5 to the third power is 125
(7.5)What is the value of x?
X
オー2
x + 5
x + ]
A
7.5
B.
10
C
2.5
D
5
Answer:
D 5
Step-by-step explanation:
the same scaling factor s applies to all sides when transforming from the small to the large triangle.
x×s = x + 5
(x-2)×s = x +1
=> s = (x+5)/x
=> (x-2)×(x+5)/x = x + 1
=> x² + 3x - 10 = x² + x
=> 3x - 10 = x
=> 2x = 10
=> x = 5
There are 2 quarters, 1 nickel, and 2 dimes in a pocket.
What is the probability of choosing a coin, not returning it to the pocket, and then choosing another of greater value?
A ^3 10
B ^6 25
C ^4 10
D ^8 25
Answer:
C
Step-by-step explanation:
please help!!!!!! i will mark brainliest!
Answer:
d
Step-by-step explanation:
KLM is isosceles. Calculate the segment EF from the data in the drawing.
HELP!!
Answer:
4.5 cm
Step-by-step explanation:
KL = LM as triangle is isosceles
LM = KM as LF = FM = KN = NM, so the triangle is equilateral
EF ║ NM as LE⊥EF and LN⊥NM
EF is half the midsegment as ∠KLN ≅ ∠MLN, and LN is angle bisector of ∠KLM
Midsegment is half the side length, and all sides are 18 cm.
EF = 1/2(1/2*18) = 4.5 cm
Please help me with at least one problem i’m sort of confused on them but I was able to get one. And I will mark brainiest
Answer:
1. 5.75 * 33 = $189.75
The bakers income is $189.75
2. 2 * y - 8 / 4 when y = 7
2 * 7 - 8 / 4 = 12
3. 76 + 4 * y^2 + 1 when y = 3
76 + 4 * 3^2 + 1 = 113
Expand the logarithm. Assume all expressions exist and are well-defined.
Write your answer as a sum or difference of common logarithms or multiples of common
logarithms. The inside of each logarithm must be a distinct constant or variable.
log 3y
Answer:
Step-by-step explanation:
log 3y = log(y)^3 (exponent)
or
= log(y)*log(y)*log(y) (multiples)
The logarithmic expression y = log(3y) can be written as sum or difference of common logarithms as log(3y) = log(3) + log(y).
What is logarithm? What is a mathematical function, equation and expression?logarithmic : It is a quantity representing the power to which a fixed number (the base) must be raised to produce a given number. Mathematically -[tex]$\log_{b}({b^x})=x[/tex] {where [b] is logarithmic base}
function : In mathematics, a function from a set X to a set Y assigns to each element of X exactly one element of Y. The set X is called the domain of the function and the set Y is called the codomain of the function.expression : A mathematical expression is made up of terms (constants and variables) separated by mathematical operators.equation : A mathematical equation is used to equate two expressions.Given is the following logarithmic expression as -
y = log(3y)
We have the following logarithmic expression -
y = log(3y)
Using the identity of logarithm -
log(AB) = log(A) + log(B)
log(3y) = log(3) + log(y)
Therefore, the logarithmic expression y = log(3y) can be written as sum or difference of common logarithms as log(3y) = log(3) + log(y).
To solve more questions on functions, expressions and polynomials, visit the link below -
brainly.com/question/17421223
#SPJ2
WILL GIVE BRAILIEST!!!
Answer:
Step-by-step explanation:
6^4*612/6^7
6^4*6^12-7
6^4*6^5
6^4+5
6^9
A cell phone company offers two texting plans to its customers. The monthly cost, y dollars, of plan A is
y =0.16x +9, where x is the number of texts. The cost of plan B is shown in the table. Drag and drop the
correct option into the box to make the statement true.
Answer: plan B is cheaper
Step-by-step explanation:
A . What is the slope in the line of the graph ?
Answer:
0.2x+3
Step-by-step explanation:
10 points !
what is 20% of 30 ?
Answer:
6
Step-by-step explanation:
Of means multiply
20% * 30
Change to decimal form
.20 * 30
6
Answer:
6
Step-by-step explanation:
[tex]20\% \ of \ 30 = \frac{20}{100} \times 30 = \frac{1}{5} \times 30 = 6[/tex]
Item 4
Find the surface area of the prism.
The surface area is
a
square feet.
Answer:
xnxnxnzznchamschdntjekdfurnthsjdnfjdjdjdkdkr
Step-by-step explanation:
xmxmxnxmxmxnxmxnxndmsndfhakxufmrjdkxddjrf7sjrifxisufkf8dhrkfdkshgshdbfjdddnfjfkdnfmcmcmdmdkfkfkkfdkfkfkfkfkfkfkfkkfkfkfkfkfkdkdkdmdkdkdkdkdmdmrmddmrm1520195126152019512615201951261520195126152019512615201951261520195126152019512615201951261520195126152019512615201951261520195126152019512615201951261520195126152019512615201951261520195126152019512615201951261520195126152019512615201951261520195126152019512615201951261520195126152019512615201951261520195126