The y intercept on a graphed equation is where the graphed equation crosses the y axis. x would equal zero at this spot. In a linear equation such as y = mx +b where m is the slope, b is the y intercept. Lets look at the equation y= 3x + 7 the slope is 3 and the y intercept is 7 So if they give you any linear equation put it in the form of y = mx +b first and your b will be the y intercept. Example 3y -x =15. I change this to 3y = x + 15 by adding x to each side. Now I change this to y = 1/3x +5 by dividing each side by 3. The slope of the original equation is 1/3 and the y intercept is 5.