8.+Literal+Equations

Exercise 38.
First of all, this formula is used to find the permiter of a rectangle. However, what we need to do in this exercise is to solve W (width).
 * First, we switch 2L to the left keeping in mind the every time we switch a variable its sign will change as well. So it should look like this:

P - 2L = 2W


 * Second, in order to isolate only W, we should divide evrything by 2.

P/2 - 2L/ 2 = 2W/2


 * Third, we simplify same terms and the answer should be:

P/2 - L = W or W= P/2 - L