The phrase a number means an arbitrary variable. We can pick any letter a-z except for i and e. Let's choose x. Twice a number means we multiply x by 2: 2x ten added to twice a number 2x + 10 The phrase is the same as means equal to. Set 25 equal to 2x + 10 to get our algebraic expression 25 = 2x + 10 If the problem asks you to solve for x, type it in our math solver and get x = 7.5
