Question

(а2+1)2-(а2-1)2
___________ = 4
а

Answer 1

$frac{(a^2+1)^2-(a^2-1)^2}{a}=4$
$frac{a^4+2a^2+1-(a^4-2a^2+1)}{a} =4$
$frac{4a^2}{a} =4$
$4a=4$
$a=1$
Ответ:$1$