Answer: +3 and -3, and + 2i or - 2i, which is the second answer.
Step-by-step explanation:
(x^2 -9)(x^2 + 4) is the factorization. Now set each side equal to zero:
(x^2-9) = 0; so x^2= 9, and x = square root of 9 which is +3 or -3.
(x^2) + 4 = 0; so x^2 = -4, and x will equal the square root of NEGATIVE 4, which is plus or minus 2i
