I'm Sorry for all the work. I swear this is the last one! Please just help me in this last question.....

Answer:
Step-by-step explanation:
y=mx+b where m=slope and b=y intercept
m=(y2-y1)/(x2-x1), we have points (0,0) and (4,12)
m=(12-0)/(4-0)=12/4=3
y=3x+b, using point (4,12) we can solve for b
12=3(4)+b
12=12+b
b=0 so the line is
y=3x