1. a) -x^2-4x+5>0
x^2+x-5x+5>0
-x * ( x-1) - 5 (x -1) > 0
- (x-1) * (x+5) > 0
0} \atop {x+5>0}} \right. \left \{ {{x < 1} \atop {x> -5}} \right.
\left \{ {{- (x > 1} \atop {x < - 5}} \right. " alt=" \left \{ {{- (x- 1) > 0} \atop {x+5>0}} \right. \left \{ {{x < 1} \atop {x> -5}} \right.
\left \{ {{- (x > 1} \atop {x < - 5}} \right. " align="absmiddle" class="latex-formula">
x = (-5 , 2)
x = ∞
x = (-5 , 1)