x 3
Step-by-step explanation:
On an exam a student earned a grade of 80. On the retake they earned a grade of 100. What is the percent increase in the grade?
Answer:
25%
Step-by-step explanation:
Percentage increase from 80 to 100 making the increase 25%
Answer:
16 percent sorry if im wrong i tried
Step-by-step explanation:
A cable TV company charges $28 for the basic service plus $8 for each movie channel. Let y be the total cost
in dollars of subscribing to cable TV, using x movie channels. Find the slope-intercept form of the equation.
Look at pic
Answer:
y= 28x+8
Step-by-step explanation:
Chris lost 4 of the 10 dollar bills that his parents gave him for his birthday. What percentage of his dollar bills did he lose?
Answer:
Step-by-step explanation:
Percentages are always out of 100 and can be illustrated by fractions.
[tex]\frac{4}{10}[/tex] [tex]\frac{x}{100}[/tex]
To find out x, you multiply 100x4 then divide by 10.
This leaves us with [tex]\frac{40}{100}[/tex]
Which is also 40%.
How many solutions does
Y = 2x + 10
3y - 6x = 30
Show all work
A no solution
B one solution
C infinity solutions
Answer:
A no solution
Step-by-step explanation:
y = 2x + 10
3y - 6x = 30
3(2x+10) -6x =30
6x +30 -6x =30
6x -6x = 30-30
0=0
How do I evaluate this using trigonometric substitution?
∫dx/(81x^2+4)^2
Answer:
[tex]\displaystyle \frac{1}{144}arctan(\frac{9x}{2}) + \frac{x}{8(81x^2 + 4)} + C[/tex]
General Formulas and Concepts:
Alg I
Terms/CoefficientsFactorExponential Rule [Dividing]: [tex]\displaystyle \frac{b^m}{b^n} = b^{m - n}[/tex]Pre-Calc
[Right Triangle Only] Pythagorean Theorem: a² + b² = c²
a is a legb is a legc is hypotenuseTrigonometric Ratio: [tex]\displaystyle sec(\theta) = \frac{1}{cos(\theta)}[/tex]
Trigonometric Identity: [tex]\displaystyle tan^2\theta + 1 = sec^2\theta[/tex]
TI: [tex]\displaystyle sin(2x) = 2sin(x)cos(x)[/tex]
TI: [tex]\displaystyle cos^2(\theta) = \frac{cos(2x) + 1}{2}[/tex]
Calc
Integration Rule [Reverse Power Rule]: [tex]\displaystyle \int {x^n} \, dx = \frac{x^{n + 1}}{n + 1} + C[/tex]
Integration Property [Multiplied Constant]: [tex]\displaystyle \int {cf(x)} \, dx = c \int {f(x)} \, dx[/tex]
IP [Addition/Subtraction]: [tex]\displaystyle \int {[f(x) \pm g(x)]} \, dx = \int {f(x)} \, dx \pm \int {g(x)} \, dx[/tex]
U-Substitution
U-Trig Substitution: x² + a² → x = atanθ
Step-by-step explanation:
Step 1: Define
[tex]\displaystyle \int {\frac{dx}{(81x^2 + 4)^2}}[/tex]
Step 2: Identify Sub Variables Pt.1
Rewrite integral [factor expression]:
[tex]\displaystyle \int {\frac{dx}{[(9x)^2 + 4]^2}}[/tex]
Identify u-trig sub:
[tex]\displaystyle x = atan\theta\\9x = 2tan\theta \rightarrow x = \frac{2}{9}tan\theta\\dx = \frac{2}{9}sec^2\theta d\theta[/tex]
Later, back-sub θ (integrate w/ respect to x):
[tex]\displaystyle tan\theta = \frac{9x}{2} \rightarrow \theta = arctan(\frac{9x}{2})[/tex]
Step 3: Integrate Pt.1
[Int] Sub u-trig variables: [tex]\displaystyle \int {\frac{\frac{2}{9}sec^2\theta}{[(2tan\theta)^2 + 4]^2}} \ d\theta[/tex][Int] Rewrite [Int Prop - MC]: [tex]\displaystyle \frac{2}{9} \int {\frac{sec^2\theta}{[(2tan\theta)^2 + 4]^2}} \ d\theta[/tex][Int] Evaluate exponents: [tex]\displaystyle \frac{2}{9} \int {\frac{sec^2\theta}{[4tan^2\theta + 4]^2}} \ d\theta[/tex][Int] Factor: [tex]\displaystyle \frac{2}{9} \int {\frac{sec^2\theta}{[4(tan^2\theta + 1)]^2}} \ d\theta[/tex][Int] Rewrite [TI]: [tex]\displaystyle \frac{2}{9} \int {\frac{sec^2\theta}{[4sec^2\theta]^2}} \ d\theta[/tex][Int] Evaluate exponents: [tex]\displaystyle \frac{2}{9} \int {\frac{sec^2\theta}{16sec^4\theta} \ d\theta[/tex][Int] Rewrite [Int Prop - MC]: [tex]\displaystyle \frac{1}{72} \int {\frac{sec^2\theta}{sec^4\theta} \ d\theta[/tex][Int] Divide [ER - D]: [tex]\displaystyle \frac{1}{72} \int {\frac{1}{sec^2\theta} \ d\theta[/tex][Int] Rewrite [TR]: [tex]\displaystyle \frac{1}{72} \int {cos^2\theta} \ d\theta[/tex][Int] Rewrite [TI]: [tex]\displaystyle \frac{1}{72} \int {\frac{cos(2\theta) + 1}{2}} \ d\theta[/tex][Int] Rewrite [Int Prop - MC]: [tex]\displaystyle \frac{1}{144} \int {cos(2\theta) + 1} \ d\theta[/tex][Int] Rewrite [Int Prop - A/S]: [tex]\displaystyle \frac{1}{144} [\int {cos(2\theta) \ d\theta + \int {1} \ d\theta][/tex]Step 4: Identify Sub Variables Pt.2
Determine u-sub for trig int:
u = 2θ
du = 2dθ
Step 5: Integrate Pt.2
[Ints] Rewrite [Int Prop - MC]: [tex]\displaystyle \frac{1}{144} [\frac{1}{2} \int {2cos(2\theta) \ d\theta + \int {1 \theta ^0} \ d\theta][/tex][Int] U-Sub: [tex]\displaystyle \frac{1}{144} [\frac{1}{2} \int {cos(u) \ du + \int {1 \theta ^0} \ d\theta][/tex][Ints] Integrate [Trig/Int Rule - RPR]: [tex]\displaystyle \frac{1}{144} [\frac{1}{2} sin(u) + \theta + C][/tex][Expression] Back Sub: [tex]\displaystyle \frac{1}{144} [\frac{1}{2} sin(2 \theta) + arctan(\frac{9x}{2}) + C][/tex][Exp] Rewrite [TI]: [tex]\displaystyle \frac{1}{144} [\frac{1}{2}(2sin(\theta)cos(\theta)) + arctan(\frac{9x}{2}) + C][/tex][Exp] Multiply: [tex]\displaystyle \frac{1}{144} [sin(\theta)cos(\theta) + arctan(\frac{9x}{2}) + C][/tex][Exp] Back Sub: [tex]\displaystyle \frac{1}{144} [sin(arctan(\frac{9x}{2}))cos(arctan(\frac{9x}{2})) + arctan(\frac{9x}{2}) + C][/tex]Step 6: Triangle
Find trig values:
[tex]\displaystyle tan\theta = \frac{9x}{2}[/tex]
[tex]\displaystyle \theta = arctan(\frac{9x}{2})[/tex]
tanθ = opposite / adjacent; solve hypotenuse of right triangle, determine trig ratios:
sinθ = opposite / hypotenuse
cosθ = adjacent / hypotenuse
Leg a = 2
Leg b = 9x
Leg c = ?
Sub variables [PT]: [tex]\displaystyle 2^2 + (9x)^2 = c^2[/tex]Evaluate exponents: [tex]\displaystyle 4 + 81x^2 = c^2[/tex][Equality Property] Square root both sides: [tex]\displaystyle \sqrt{4 + 81x^2} = c[/tex]Rewrite: [tex]c = \sqrt{81x^2 + 4}[/tex]Substitute into trig ratios:
[tex]\displaystyle sin\theta = \frac{9x}{\sqrt{81x^2 + 4}}[/tex]
[tex]\displaystyle cos\theta = \frac{2}{\sqrt{81x^2 + 4}}[/tex]
Step 7: Integrate Pt.3
[Exp] Sub variables [TR]: [tex]\displaystyle \frac{1}{144} [\frac{9x}{\sqrt{81x^2 + 4}} \cdot \frac{2}{\sqrt{81x^2 + 4}} + arctan(\frac{9x}{2}) + C][/tex][Exp] Multiply: [tex]\displaystyle \frac{1}{144} [\frac{18x}{81x^2 + 4} + arctan(\frac{9x}{2}) + C][/tex][Exp] Distribute: [tex]\displaystyle \frac{1}{144}arctan(\frac{9x}{2}) + \frac{x}{8(81x^2 + 4)} + C[/tex]You are going to Wal-Mart to buy DVD's. The DVD'sare packaged in a box. There are thirty five DVDs in the box. You only want five. The box cost forty-five dollars. How much did you pay? How much change do you get back if you pay with fifty dollars? Explain the order of operations that was used.
Answer:
DVD sales have been on the decline for over a decade, but a slew of new streaming services and a shift in how consumers are watching movies and TV shows could be the final death knell for the technology.
The same can be said for Blu-Ray discs.
At its peak, DVD sales reached $16.3 billion and were 64% of the U.S. home video market. That was 2005. These days, DVD sales account for less than 10% of the total market, with total sales hitting $2.2 billion in 2018.
Blu-Ray discs, which have always been slightly more expensive than DVDs, launched in 2006. At most, Blu-Ray sales reached $2.37 billion in 2013, before falling to $1.8 billion in 2018. It’s likely that Blu-Ray sales fractionally impacted the decline of DVD sales, but the fact that DVD sales still outpace Blu-Ray sales shows it’s not the real culprit.
Instead, a combination of the Great Recession, a rise in customers buying on-demand and digital copies of films and the launch of streaming services is what has caused DVD sales to decline more than 86% in the last 13 years.
Step-by-step explanation:
use the bar diagram to help you solve the equation 4x-12=16.
Answer:
x = 7
Step-by-step explanation:
4x−12=16
Step 1: Add 12 to both sides.
4x−12+12=16+12
4x=28
Step 2: Divide both sides by 4.
4x/4 = 28/4 = 7
x=7
5. The daily temperature recorded (in degree F) at a place during a week was as under:
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
35.5
30.8
27.3
32.1
23.8
29.9
Find the mean temperature.
Answer:
29.9 °F
Step-by-step explanation:
The formular for mean is given as;
Mean = Sum of Terms / Number of terms
Number of terms = 6
Sum of terms = 35.5 + 30.8 + 27.3 + 32.1 + 23.8 + 29.9 = 179.4
Mean = 179.4 / 6 = 29.9
Can someone please help me!!
Answer:
B.
Step-by-step explanation:
$3.50 nail polish marked up to $8.75. explain it please like example.
Answer:
the pice goes up 5.25 more i dont get what is asked btw
Step-by-step explanation:
Answer:
150%
Step-by-step explanation:
Sorry I don't know how to explain this since I just got this from my test.
Evaluate Sin^-1 sqrt2/2
Step-by-step explanation:
Let x = arcsin(√2/2).
We have sinx = √2/2, which is a basic trignometry identity. (sin45° = √2/2)
Since the range of arcsinx is [-90°, 90°] and 45° is within the range, the answer is 45° or π/4.
Please help due in 5 mins
Answer:
2/5 decimal: 0.4. percent:40%
Answer: 0.4 / 40%
Step-by-step explanation:
Decimal 0.4
Percentage 40%
PLZ HELP ITS DUE TONIGHT
Because two pairs of angles are congruent, the triangles are similar by
the (select)
QR=
AA Criterion.
QR is similar to BC
Hope it helps.
Rebecca uses 3/4 gallon of paint to cover 1 wall. She has 3 gallons of paint how many 3/4s for into 3
Answer:
12
Step-by-step explanation:
Given that 4x - 5y = 12 find y when x= -3
Answer:
y ⁻²⁴⁄₅ or - 4.8Explanation:
4x - 5y = 12
x = -3
Insert -3 for 'x' in the equation4(-3) - 5y = 12
Remove the parentheses: (-a) = -a-4 · 3 - 5y = 12
Multiply 4 · 3: 12-12 - 5y = 12
Add 12 to both sides of the equation-12 - 5y + 12 = 12 + 2
Simplify-5y = 24
Divide both sides by -5-5y / -5 = 24 / -5
Simplifyy = ⁻²⁴⁄₅
Turn the fraction into a decimaly = -4.8
a marble travel 300 cm in 6 seconds on the roller coaster what is the marble speed
Answer:
50
Step-by-step explanation:
Answer: 50 cm/s
Step-by-step explanation:
The formula for speed is: s=d/t
s=speedd=distancet=time----------------------------------------------------------------------------
Given
d=300 cm
t=6 s
Solve
s=d/t
s=(300)/(6)
s=50 cm/s
Hope this helps!! :)
Please let me know if you have any questions
$1900 at 9 for 2 years
Answer:
$342
Step-by-step explanation:
Complete question
Find the simple interest on $1900 at 9% for 2 years.
Simple interest PRT/100
Given
Principal P = 1900
Rate R = 9%
Time T = 2years
Substitute
Simple interest = 1900*9*2/100
Simple interest = 19*18
Simple interest = $342
Hence the simple interest on $1900 at 9% for 2 years is $342
I paid 7% tax on a vest. If the tax was $1.47, what was the cost of
the vest?
Answer:
21
Step-by-step explanation:
Answer:
cost of vest is $21.00
Step-by-step explanation:
set up and equation:
let x be cost of vest
0.07x=1.47
÷0.07 ÷0.07
x= 21
Which equation represents a line which is parallel to the line
y= 2x – 8?
Answer: y=2x
Step-by-step explanation:
A plane travels 1820 meters at a speed of 260 m/sec. How long did it
take to reach its destination? PLEASE HELP!
Answer:
7 seconds
Step-by-step explanation:
1820/260=7.
Answer:
7m/sec
Step-by-step explanation:
What is seven and forty hundredths in standard form
Answer:
7.04
Step-by-step explanation:
Help me please quick!
Answer:
28
Step-by-step explanation:
All angles together in the triangle are 180.
62+90+x=180
x=180-(90+62)
x=180-152
x=28
Which expression shows the prime factorization of 56?
Answer:
2³×7
Step-by-step explanation:
Use the slope formula to determine the slope of the line containing the two points.
(-1, -7) and (-6, -3)
A. 10/7
B. -4/5
C. -1/2
D. -5/4
What is the value of x in the matrix equation below?
Answer:
Where? Provide it please.
Step-by-step explanation:
aaaaaaaaaaaaaaaaaaaadasadadsdasadsdasad
Answer:
D) is correct
Step-by-step explanation:
4/5 divided by 3/4 =
Answer:
16/15 or 1 1/15
Step-by-step explanation:
4/5 divided by 3/4
Flip 3/4 so it is 4/3
Multiply 4/5 by 4/3
16/15
Write an equation of the line that passes through (8.1) and is perpendicular to the line 2y + 4x = 12
Answer:
The equation of the perpendicular line is 2x-4y -12=0
Step-by-step explanation:
Explanation
Given that the equation of the line is 4x+2y-12=0
The equation of the perpendicular line b x -ay +k=0
The equation of the perpendicular line 2x -4y +k=0
This line passes through the point (8,1)
2(8)-4(1)+k=0
⇒ 16 -4+k=0
⇒ 12 +k=0
k =-12
The equation of the perpendicular line is 2x-4y -12=0
simplify this, please
Answer:
what is it because I don't see it
Answer:
simplify what?
Step-by-step explanation:
so like simplify this or please or both. if so then... the is this (i guess) and please is pls, (i guess)
what is the equivalent ratio of 2 over 9?