Ask question

Ask question

All categories

aleksandrvk [35]

3 years ago

5

Solve for x I need this done by tonight please help

2 answers:

Alexandra [31]3 years ago

8 0

Answer:

x= 20

Step-by-step explanation:

3/4x = 15

Multiply each side by 4/3 to isolate x

4/3 * 3/4x = 15 * 4/3

x = 20

Bess [88]3 years ago

7 0

Answer:

D

Step-by-step explanation:

3x/4=15. Times both sides by 4, 3x=60. Divide both sides by 3, which then x=20.

You might be interested in

For 0 ≤ ϴ < 2π, how many solutions are there to tan(StartFraction theta Over 2 EndFraction) = sin(ϴ)? Note: Do not include va

Black_prince [1.1K]

Answer:

3 solutions:

$\theta={0, \frac{\pi}{2}, \frac{3\pi}{2}}$

Step-by-step explanation:

So, first of all, we need to figure the angles that cannot be included in our answers out. The only function in the equation that isn't defined for some angles is $tan(\frac{\theta}{2})$ so let's focus on that part of the equation first.

We know that:

$tan(\frac{\theta}{2})=\frac{sin(\frac{\theta}{2})}{cos(\frac{\theta}{2})}$

therefore:

$cos(\frac{\theta}{2})\neq0$

so we need to find the angles that will make the cos function equal to zero. So we get:

$cos(\frac{\theta}{2})=0$

$\frac{\theta}{2}=cos^{-1}(0)$

$\frac{\theta}{2}=\frac{\pi}{2}+\pi n$

or

$\theta=\pi+2\pi n$

we can now start plugging values in for n:

$\theta=\pi+2\pi (0)=\pi$

if we plugged any value greater than 0, we would end up with an angle that is greater than $2\pi$ so, that's the only angle we cannot include in our answer set, so:

$\theta\neq \pi$

having said this, we can now start solving the equation:

$tan(\frac{\theta}{2})=sin(\theta)$

we can start solving this equation by using the half angle formula, such a formula tells us the following:

$tan(\frac{\theta}{2})=\frac{1-cos(\theta)}{sin(\theta)}$

so we can substitute it into our equation:

$\frac{1-cos(\theta)}{sin(\theta)}=sin(\theta)$

we can now multiply both sides of the equation by $sin(\theta)$

so we get:

$1-cos(\theta)=sin^{2}(\theta)$

we can use the pythagorean identity to rewrite $sin^{2}(\theta)$ in terms of cos:

$sin^{2}(\theta)=1-cos^{2}(\theta)$

so we get:

$1-cos(\theta)=1-cos^{2}(\theta)$

we can subtract a 1 from both sides of the equation so we end up with:

$-cos(\theta)=-cos^{2}(\theta)$

and we can now add $cos^{2}(\theta)$

to both sides of the equation so we get:

$cos^{2}(\theta)-cos(\theta)=0$

and we can solve this equation by factoring. We can factor $cos(\theta)$ to get:

$cos(\theta)(cos(\theta)-1)=0$

and we can use the zero product property to solve this, so we get two equations:

Equation 1:

$cos(\theta)=0$

$\theta=cos^{-1}(0)$

$\theta={\frac{\pi}{2}, \frac{3\pi}{2}}$

Equation 2:

$cos(\theta)-1=0$

we add a 1 to both sides of the equation so we get:

$cos(\theta)=1$

$\theta=cos^{-1}(1)$

$\theta=0$

so we end up with three answers to this equation:

$\theta={0, \frac{\pi}{2}, \frac{3\pi}{2}}$

7 0

3 years ago

7x+8x(9y-) respondaa por favorzinho

poizon [28]

Answer:

7x+72xy

Step-by-step explanation:

7x+8x(9y)=7x+72xy

3 0

3 years ago

Read 2 more answers

Plz save me I need help as sonic

Rzqust [24]

Answer:

1.Yes

2.Yes

3.No

4.No

5.Yes

Step-by-step explanation:

Just plug in the values of x and y for each set of coordinates.

Example from the first one

4x=y

4(5)=20

20=20 True

make sure all are valid by plugging in the next set of coordinates

4(6)=24

24=24 True

4(7)=28

28=28 True

and so forth with each equation plug in the coordinates

3 0

3 years ago

Read 2 more answers

PLEASE HELP MEEEE!

slava [35]

The slope is 1/2. Every time the x increases by 2, the y increases by 1. Slope is the rise over the run, which would be 1/2

6 0

3 years ago

Read 2 more answers

The expression when m=6 and n=4

AlladinOne [14]

Plugging in the values, we get 7(6)-4=42-4=38.

3 0

3 years ago

Read 2 more answers