Question

Solve (x² - 16)(x² - 9) = 0

Answer 1

x=-4,4,-3,3

Explanation:

Factor by the difference of two squares

`{x}^(2) - {y}^(2) = (x + y)(x - y)`

`{x}^(2) - 16 = (x + 4)(x - 4) \\ {x}^(2) - 9 = (x + 3)( x - 3)`

`(x + 4)(x - 4)(x + 3)(x - 3) = 0`

Therefore, our answer is x = -4,4,-3,3