So, this is a long and complicated question to explain. First you must get x on one side and y on the other (getting the other number w/o a variable with the x). So you should get to this format: y=mx+b
m=slope and b= initial number
first you subtract 12x on both sides, which will leave you with 3y=-12x+72.
Then, you must divide both sides by 3, leaving you with: y=-4x+24
So, thats your answer! The point where the line hits the x=0 is y=24. Hope this helps, and if you have any further questions, please let me know!
