1. 2y+6=21-3y
2y+3y=21-6
5y=15
y=15:5
y=3
2. 2-c+3c-9=-13
2c=-13+7
c=-6:2
c=3
3. -3+9b-12=2
9b=2+15
b=17/9
b=1 8/9
1. 2y+6=21-3y
2y+3y=21-6
5y=15
y=15:5
y=3
2. 2-c+3c-9=-13
2c=-13+7
c=-6:2
c=3
3. -3+9b-12=2
9b=2+15
b=17/9
b=1 8/9