You have to distribute the 4 to the numbers in the parenthesese. So 4 times 3x which is 12x and 4 times 5 which is 20 so now you get 12x plus 20 equals 8. Now you have to subtract 20 from 8 which is -12 so now you have 12x=-12 now divide the 12 from x and 12 from -12 and so now you have x=-1