Question

Solve the formula P = 2l + 2w for w.

Answer 1

First isolate your "w" value by moving 2l to the other side by subtracting it from both sides:

P - 2l = 2w

Now divide both sides by 2:
P/2 - 2l/2 = 2w/2

which is the same as:
P/2 - l = w

So w = P/2-l