SOLUTION: What is the equation of the line passing through (-3,2) with y-intercept two thirds of the x-intercept.

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Question 1078800: What is the equation of the line passing through (-3,2) with
y-intercept two thirds of the x-intercept.

Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
What is the equation of the line passing through (-3,2) with
y-intercept two thirds of the x-intercept.

Let's draw an arbitrary line through (-3,2) that crosses the
y-axis at (0,b), where "b" is the y-intercept, and the x-axis
at (a,0) where "a" is the x-intercept.



Using the distance formula on (0,b) and (a,0) we find that
the slope is 

m=%280-b%29%2F%28a-0%29%22%22=%22%22-b%2Fa

Since we are told that the y-intercept "b" is two-thirds of the
x-intercept "a", we can write

b%22%22=%22%22expr%282%2F3%29a

So the slope is m%22%22=%22%22-b%2Fa%22%22=%22%22-%28expr%282%2F3%29a%29%2Fa%5E%22%22%22%22=%22%22-expr%282%2F3%29a%2Aexpr%281%2Fa%29%22%22=%22%22-expr%282%2F3%29cross%28a%29%2Aexpr%281%2Fcross%28a%29%29%22%22=%22%22-2%2F3

We use the point slope formula to find the equation
of the line through the point (-3,2) with slope m%22%22=%22%22-2%2F3:

y-y%5B1%5D%22%22=%22%22m%28x-x%5B1%5D%29

y-2%22%22=%22%22expr%28-2%2F3%29%28x-%28-3%29%5E%22%22%29

y-2%22%22=%22%22expr%28-2%2F3%29%28x%2B3%5E%22%22%29

y-2%22%22=%22%22expr%28-2%2F3%29x-2

y%22%22=%22%22expr%28-2%2F3%29x

So the line goes through the origin and has this graph:


So we see that the x-intercept and the y-intercept are both zero,
and they coincide at the origin (0,0).  And, surprisingly, that's 
correct, since two-thirds of zero is indeed zero!  :)

Answer:  y%22%22=%22%22expr%28-2%2F3%29x

Edwin