Question

Factor the expression completely.

x^4-11x^2+28
x
4
−11x
2
+28

Answer 1

(x² - 7)(x² - 4)

Explanation:

We can actually factor this the same way we would solve a normal quadratic equation. We will end up with the factored terms have squares of x instead of just x.

x⁴ - 11x² + 28

= x⁴ - 4x² - 7x² + 28

= x²(x² - 4) - 7(x² - 4)

= (x² - 7)(x² - 4)