Question

Разложить на множители
9а²-4b²

Answer 1

$9a^2-4b^2=(3a)^2-(2b)^2=(3a-2b)(3a+2b)\\\\\\\boxed {\ x^2-y^2=(x-y)(x+y)\ }$

Answer 2

(3а-2b)(3a+2b)=9a^2-4b^2