Question

Solve for the indicated variable in each mathematical formula.


`1. C=2\pi r` for r


`2. A=(1)/(2) bh` for b

3. y=mx+b for x

Help please)

Answer 1

So to solve for a variable, your goal is to isolate that variable onto one side.

1.

For this, divide both sides by 2π and your answer will be
`(C)/(2\pi )=r`

2.

Firstly, divide both sides by h:
`(A)/(h)=(1)/(2)b`

Next, multiply both sides by 2 and your answer will be
`(2A)/(h)=b`

3.

Firstly, subtract both sides by b:
`y-b=mx`

Next, divide both sides by m and your answer will be
`(y-b)/(m)=x`

Answer 2

1. C=2πr

We need to move r by itself on a side of the equation.

Divide both sides of the equation by 2π. This will cancel out the side with the r.

r=C/2π

2. A=1/2*b*h

Divide both sides by 1/2*h, isolating b

b=A/
`(1)/(2)`h

3.y=mx+b

Now we have to do reverse PEMDAS, we have to add/subtract before we can multiply or divide to simplify.

Subtract both sides by b

y-b=mx

Now divide both sides by m

x=
`(y-b)/(m)`

Remember we have to divide both terms y and -b by 2, so it goes on the bottom for both.