Answer:
3x=18
Step-by-step explanation:
We want to get the variable x by itself.
Since we see a -3 with the 3x, we want to move the 3 to the other side of the equal sign by adding 3 to both sides of the equal sign.
3x - 3 = 15
3x - 3 + 3 = 15 + 3
Then we get:
3x + 0 = 18
3x = 18
