Question

P(-3)=x^3+5; evaluate P(-3)

Answer 1

You are given P(x) = x^3 + 5, not P(-3).  You are to evaluate the function at x=-3.

The function is P(x)=x^3+5.  Let's now replace x with (-3):

P(-3) = (-3)^3 + 5     =     -27 + 5 = -22 (answer)