Question

How do you solve this problem

Answer 1

Pretty sure it’s d, since z = (x^2 + x)(x^2 + x) + x^2 + x

Answer 2

y = x^2 + x

z = y^2 + y

substitute y = x^2 + x into z = y^2 + y

z = (x^2 + x)^2 + (x^2 + x)

z = x^4 + 2x^3 + x^2 + x^2 + x

z = x^4 + 2x^3 + 2x^2 + x

Answer is

x^4 + 2x^3 + 2x^2 + x