4x-28x :2 + 9x- 9x:3 = 4x-14x+9x-3x = =13x-17x=4
4x(X-7):2+9x(X-1):3 = 4x²-28x :2 + 9x²- 9x:3 = 4x²-14x+9x²-3x = =13x²-17x