a) 3(x-1)-3=0
3x-3-3=0
3x-6=0
3x=6/:3
x=2
b) 6y+2(y+1)-18=0
6y+2y+2-18=0
8y-16=0
8y=16/:8
y=2
c) 6-t=t+2
-t-t=2-6
-2t=-4/:(-2)
t=2
