Answer: y=4
Step-by-step explanation: First we have to distribute the numbers in front of our factors: 3*y-3*1=3y-3
2*2y+2*6=4y+12
3y+7+3y-3=4y+12
Next we combine like terms on the same side:
3y+3y=6y
7-3=4
6y+4=4y+12
Then combine like terms on opposite sides and get y by itself:
6y-4y=2y
12-4=8
2y=8
Finally divide to isolate y:
y=8/2
y=4