You can put this solution on YOUR website! How do you find the y-intercept, meaning (0,b), with a slope, meaning m, and ordered pair, something like known point (p,r)?
Assume you have slope-intercept form for a line. y=mx+b.
Solve for b, since that is what you are looking for.
b=y-mx
Substitute your given information. DONE in general. Supply your actual given values for your specific question.