12xв квадрате -5x+(1+3x)(1-3x)-3(x-2)(x+3)-6=21

Question

12xв квадрате -5x+(1+3x)(1-3x)-3(x-2)(x+3)-6=21

Answer 1

12х²-5х+(1-9х²)-3(х²+3х-2х-6)-6-21=0
12х²-5х+1-9х²-3х²-9х+6х+18-27=0
-5х+1-3х-9=0
-8х-8=0
-8(х+1)=0   (:-8)
(х+1)=0
х+1=0
х=-1
Ответ:   х=-1