(f.g)(x) = f (g(x))= f ( x^4+3)
= (x^4+3)^2 + 2 ( x^4+3) - 6
= x^8 + 9 + 6x^4 + 2x^4 + 6-6
= x^8 + 8x^4+9
4x+12=90
4x=90-12
4x=8
x=8/4
x=2
Answer:
D
Step-by-step explanation:
Since they are the same variables
answer -10
Answer: a
just took test edg2020
