Question

What substitution should be used to rewrite 16(x3 + 1)2 – 22(x3 + 1) – 3 = 0 as a quadratic equation?
u = (x3)
u = (x3 + 1)
u = (x3 + 1)2
u = (x3 + 1)3

Answer 1

Let u = x^3 + 1. Then 16(x^3 + 1)^2 − 22(x^3 + 1) − 3 = 0 becomes 16u^2 − 22u − 3 = 0, a quadratic in u.