SOLUTION: Do the points (3,-4),(18,6), and (9,0) all fall on the same line? If so what is the equation of the line.

Algebra ->  Linear-equations -> SOLUTION: Do the points (3,-4),(18,6), and (9,0) all fall on the same line? If so what is the equation of the line.      Log On


   

Question 370364: Do the points (3,-4),(18,6), and (9,0) all fall on the same line? If so what is the equation of the line.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!

It looks like they do but you need to calculate the slope between each set of points to be sure.
m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29
m%5B12%5D=%286-%28-4%29%29%2F%2818-3%29=10%2F15=2%2F3
m%5B23%5D=%280-6%29%2F%289-18%29=-6%2F-9=2%2F3
Yes, since they have the same slope they are on the same line.
Use the slope-intercept form, y=mx%2Bb
y=%282%2F3%29x%2Bb
Use any point to solve for b
6=%282%2F3%2918%2Bb
b=6-12
b=-6
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highlight%28y=%282%2F3%29x-6%29
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