f(x)=(9x^2–8)^6(4x^2–5)^11

Question

Find f'(x)

I got

(9x^2-8)^6 *11(4x^2-3)^10*8x+((4x^2-3)^11)6(9x^2-8)^5(18x)

but im doing something wrong can someone check my work please

Answer 1

I don't see an error. How do you know it is wrong?