Solve each formula for the indicated variable. Homework?

Question

How do i do this?
V=(pi)/3 r^2h solve for h
S=L(1 - r) solve for r
S=lw + wh + lh solve for w (the l's look like slant height l's if that helps)

Solve for x. State any restrictions on the variables:
4/9(x +3) = g
a(x +c) = b(x - c)

I sure could use some help.

So V=(pi)/3 r^2h h=3v/pi r^2
S=L(1 - r) r= S/L1 Lr?
S=lw + wh + lh w = S/L 2h?

If that is right how do i do this down here?
Solve for x. State any restrictions on the variables:
4/9(x +3) = g
a(x +c) = b(x - c)

Answer 1

This is basic algebraic manipulation. You need to understand the inverse operations.

The first case was already explained to you.

For:
S = L (1-r)

Divide both sides by L (since multiplication takes precedence, you need to undo the multiplication first).

S/L = 1 - r

Now subtract 1 from both sides:
S/L - 1 = -r

Now divide by -1:
1 - S/L = r
r = 1 - S/L

For:
S = lw + wh + lh

Subtract lh from both sides:
S - lh = lw + wh

Now distribute out the w:
S - lh = w ( l + h)

Divide both sides by (l + h)
( S - lh ) / ( l + h ) = w
w = ( S - lh ) / ( l + h )

For the last two, it's the same principle, but you need to watch if you are doing anything illegal like dividing by 0...

Answer 2

You need to get the variable by itself. I'll show you the first one.

V = pi/3 r^2 h
V/pi = 1/3 r^2 h
3V/pi = r^2 h
3V/(pi r^2) = h