So half a number means 1/2(x) 21 less than half a number is 1/2(x)-21 And four times a number means 4x So if we put it together the equation would be: 1/2(x)-21=4x So we just solve for x Subtract .5 on each side to get -21= 3.5x Then divide 3.5 from both side and the result would be 6
