The answer is A x + 4 (x +5) = 40 multiply 4 with x and 5, you will get x + 4x + 20 = 40 then add the x with 4x and you will get 5x it should look like this; 5x + 20 = 40 now subtract 20 from 40 ; it will look like this after subtracting 5x = 20 divide by 5 on each sides and you will get x = 4