Question

Solve 7w – 3r = 15 for r. Show your work.

Answer 1

What's w?

Well without W, we just have to trial and error.

R could be 2.

   7w - 3r = 15
7w - 3(2) = 15
     7w - 6 = 15
          7w = 21
           /7     /7
            w = 3

So if W = 3, R could be 2.

Answer 2

  7w - 3r = 15
7w - 3(2) = 15
     7w - 6 = 15
          7w = 21
           /7     /7
            w = 3