1)
5(x-3)-2(x-7)+7(2x+6=7
5x-15-2x+14+14x+42-7=0
17x-34=0
17x=34 / :17
X=2
2)
11(y-4)+10(5-3y)-3(4-3y)=-6
11y-44+50-30y-12+9x+6=0
-10y=0
Y=0
3)
5(8z-1)-7(4z+1)+8(7-4z)=9
40z-5-28z-7+56-32z-9=0
-20z+35=0
-20z=-35 / : (-20)
Z=-35/-20 =7/4
Z=7/4
4)
10(3x-2)-3(5x+2)+5(11-4x)=25
30x-20-15x-6+55-20x-25=0
-5x+4=0
-5x=-4 / : (-5)
X=-4/-5
X=4/5