Question

solve x2 - 4 by x2-2x-15

Answer 1

I think it's help you little

Answer 2

$\dfrac{x^2 - 4}{x^2 - 2x - 15}$

Make the numerators the difference of 2 squares:

$=\dfrac{x^2 - 2^2}{x^2 - 2x - 15}$

Apply a² - b² = (a + b) (a - b):

$=\dfrac{(x + 2)(x - 2)}{x^2 - 2x - 15}$

Factorise the denominator:

$=\dfrac{(x + 2)(x - 2)}{(x + 3)(x - 5)}$