а) 4-=0
-х²= -4
х²=4
=2 =-2
ответ: =2 =-2
б) - =
- =
- (6+6x-12)/(x*(x-1)*(x+2))=0
-6 -6x +12 =0
-5-6x+1=0
5+6x-1=0
D= 36+ 4*5*1=36+20=56
= = 2
x=-0,6±2