For about what value(s) of x does g(x) = k(x) if g(x) = x^3 + 2x^2 and k(x) = x^3 – x^2 + 6?
a. x = ± 2.3
b. x ≈ 2.3
c. x ≈ ± 1.4
d. x ≈ 1.4