How is m=9h the same as h=

They are actually not the same if that is your actual given. You see, if you want to find an equation for a variable, you need to isolate it in one side of the equation.

If your first equation is:

And you need to find h, you need to isolate h on one side, while keeping the equation true.

So how do we do this? How do we get rid of 9 but keep the statement true? We divide 9h by 9. But whatever you do on one side of the equation, you have to do it to the other side as well or the equation will not hold. So we divide both sides by 9.

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls

2(2x + 3) = -4 + 2(2x + 5)

4x + 6 = -4 + 4x + 10

4x + 6 = 4x + 6

4x - 6 + 6 = 4x - 6 + 6

4x = 4x

x = x

unlimited solutions.