Question

(a-b) (a - b) - (a-b) (a + b)​

Answer 1

$\left(a-b\right)\left(a-b\right)-\left(a-b\right)\left(a+b\right)$

$=\left(a-b\right)^2-\left(a-b\right)\left(a+b\right)$

$=a^2-2ab+b^2-\left(a-b\right)\left(a+b\right)$

$=a^2-2ab+b^2-a^2+b^2$

$=-2ab+2b^2$

Answer 2

Step-by-step explanation:

(a-b)²-(a-b)(a+b)

a²+b²-2ab-(a²-b²)

a²+b²-2ab-a²+b²

2b²-2ab