X = novel....? = math book We know that the math book is 3 times the novel plus 8 more, so that's why we can represent the novel as "x" and the math book as "3x + 8." So we can set up the equation as "math book + novel = $54." (3x + 8) + x = $54 Combine your "x's" to get 4x (because you can only combine like terms) then subtract 8 from 54. 4x = $46 Divide x (novel) = $11.50 Then subtract $11.50 from $54 to get the price of the math book which is $42.50. To check your answer, multiply $11.50 times 3 and add 8, because we were told that the math book was 3 times $11.50 plus 8.