f '(x) = [(-40x +11)(7x - 9) - 7(-4x +3)(5x + 1)]/(7x - 9)2
= [(-280x2 + 360x + 77x - 99) - 7(-20x2 - 4x + 15x + 3)]/(7x - 9)2
= [(-280x2 + 437x - 99) + (140x2 + 28x - 105x - 21)]/(7x - 9)2
= (-140x2 +360x - 120)/(7x - 9)2
i think thats how you would solve it
hope this helps tho:)
