Here's the question you clicked on:
SupaWizMcFly
helpp almost done!! http://img594.imageshack.us/img594/9951/121026165353.png
\[y=mx+c\]They want you to find the y-intercept, c. So you need to calculate the gradient, m.\[m={\Delta y \over \Delta x}={{y_1 - y} \over {x_1 - x}}\]You have two points, plug them in and find the gradient. Then substitute the gradient and one of the points into the line equation, and solve for c.
Do it step by step. Find the gradient. What do you get?