1) (х+7)* ((х-3)-(х-8)=0
(х+7)* (х-3-х+8)=0
(х+7)*5=0
х+7=0
х=-7
2) (х-2)* ((4х-9)+(1-х))=0
(х-2)* (4х-9+1-х)=0
(х-2)*(3х-8)=0
х-2=0 х=2
3х-8=0 3х=8 х=8/3
3) (х-5)*(0.2х+8)=0
х-5=0 х=5
0.2х+8=0 0.2х=-8 х=-40
4) (х-7)*(7-(х-7))=0
(х-7)*(7-х+7)=0
х-7=0 х=7
14-х=0 х=14