1) y' = 84x^5 + 50x^4 + 24x^3
2) y = 2x^3 + 3x^2 - 6x^2 - 9x - 16x - 24 = 2x^3 - 3x^2 - 25x
y' = 6x^2 - 6x - 25
3) y' = ((2x + 2)*(x^3) - 3(x^2)*(x^2 + 2x)) / (x^6) = (2x^4 + 2x^3 - 3x^4 - 6x^3) / (x^6) = (-x^4 - 4x^3) / (x^6) = -(x^3)*(x + 4) / (x^6) = -(x+4) / (x^3)
4) y' = 25*((1 - 2x + 3x^2)^24)*(-2 + 6x) = (150x - 50)*(1 - 2x + 3x^2)^24
5) y' = -2 / (sin^2(2x - 5))
6) f(x) = 12x^2 - x^3
f '(x) = 24x - 3x^2 = 0
3x*(8 - x) = 0
x=0, x=8