Question

The equation of the line passing through (1,8) and (5,6) can be expressed in the form (x/a)+(y/b)=1. Find a.

Please help, I don't know how to put my slope intercept equation into that form. I found the slope intercept form to be y= -(1/2)x+17/2. Thanks!

Answer 1

good so far at y= -(1/2)x+17/2
multiply each term by 2
2y = -x + 17
x + 2y = 17
now, instead of the 17 you want 1, so divide each term by 17
x/17 + 2y/17 = 1

x/17 + y/(17/2) = 1 compare with x/a + y/b = 1
so a = 17, b = 17/2

btw, have you learned that if written in that form
a is the x-intercept and
b is the y-intercept, neat eh??

Answer 2

Ohh, thanks! I was actually sick the day of the class, and my teacher wasn't there in our most recent class so I just did the problems to the best of my ability, so I didn't know about that a/b form. Thanks again! :)