Question

a²-1/a - 5 если а =-4​

Answer 1

Ответ:

$a=-4\\\\\\\dfrac{a^2-1}{a-5}=\dfrac{(a-1)(a+1)}{a-5}=\dfrac{(-4-1)(-4+1)}{-4-5}=\dfrac{-5\cdot (-3)}{-9}=-\dfrac{5}{3}=-1\dfrac{2}{3}$