Question

fatore: a^2 - x^2 +a + x

Answer 1

$a^2 - x^2 + a + x = a^2 + a -x^2 + x$
⇒ $a(a + 1) -x(x + 1)$
∴ $a^2 - x^2 + a + x$ = $a(a + 1) -x(x + 1)$