The phrase a number means an arbitrary variable. We can pick any letter a-z except for i and e. Let's choose x. One-half a number means we divide x by2: x/2 The word is means equal to. We set x/2 equal to 50 for our algebraic expression x/2 = 50 If the problem asks us to solve for x, we cross multiply: x = 2 * 50 x = 100
