Question

Помогите срочно !!!!!!!!!!!!
-x^2-2x+8>0 ????????????

Answer 1

$-x^2-2x+8 textgreater 0 \ \ x^2+2x-8 textless 0 \ \ Delta=4+32=36=6^2 \ \ x_1= frac{-2-6}{2}=-4;x_2= frac{-2+6}{2}=2 \ \ iff (x-2)(x+4) textless 0 iff xin (-4;2)$