Because the line is parallel to the line y = 2/5 x + 17, the slope of the new line has to be the same as well. So far, we have y = (2/5)*x .
Now what we can do is plug in -15 for x and see what we get for y. Because we get -6, we need 18 more to make it 12. Because of that, the y-intercept is 18 to make the equation of the line y = (2/5)*x + 18.
