1)12-8х-20+5х=-8-3х=-(8+3х)
2)17х-13-20х+6=-3х-7=-(3х+7)
3)3(х-2)-5(6-2х)=3х-6-30+10х=13х-36
4)12-3(8-2х)-20х=12-24+6х-20х=-12-14х=-(12+14х)=-2(6+7х)
5)4(х-3)-7(3+2х)=4х-12-21-14х=-10х-36=-(10х+36)=-2(5х+18)
6)3(4-5х)+2(6-3х)=12-15х+12-6х=24-21х
7)10-5х-(12+6х)=10-5х-12-6х=-2-11х=-(2+11х)
8)15х+5(3-6х)-25=15х+15-30х-25=-15х-10=-(15х+10)=-5(3х+2)
9)-3х+14-5х-20=-8х-6=-(8х+6)=-2(4х+3)
10)-7(3-2х)+5(3-6х)=-21+14х+15-30х=-6-16х=-(6+16х)=-2(3+8х)