What is the y-intercept? 12x+3y=72 (solve for y)

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!

So first you need to isolate y and put the equation in slope-intercept form y=mx+b (b is the y-intercept)
Subtract 12x
12x-12x+3y=72-12x
3y=72-12x
Divide 3 
y=-4x+24
24 is the y intercept of this equation.