Question

x^2-16=0

Answer 1

x^2 - 16 = x^2 - 4^2

Given equation: a^2 - b^2 = (a + b)(a - b)

Here a = x and b = 4

So for you equation: x^2 - 4^2 = (x + 4)(x - 4)

Substitute in for the given equation: x^2 - 16 = 0

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

(x + 4) = 0 or (x - 4) = 0

x = -4 or x = 4

x = 4 or -4

Answer 2

@vanne29 do you understand?

Answer 3

yes! thank you!