Which of the following is an equation of the line with x-intercept a and y-intercept b, where ab is not equal to 0?

A) y= ax+b

B) y=bx +a

C) y= (a/b)x +a

D) y= (b/a)x +b

E) y= (-b/a)x =b

You have to reverse engineer this one a bit. You know, based on the question, that the points (*a*, 0) and (0, *b*) are on the graph. From that, you can find the slope:

Armed with that slope, and with the *y*-intercept of *b*, you can write your slope-intercept equation:

Note that this is also a question that’s quite susceptible to plugging in, if that helps you visualize it. Pick values for *a* and *b*, then plug those into each answer choice, graph them, and see which line actually goes through the points it’s supposed to. 🙂