SOLUTION: What is the equation of the line passing through the points (-3,0) and (0,-3)?

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Question 184192: What is the equation of the line passing through the points (-3,0) and (0,-3)?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

First let's find the slope of the line through the points and


Note: is the first point and is the second point .


m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 Start with the slope formula.


m=%28-3-0%29%2F%280--3%29 Plug in y%5B2%5D=-3, y%5B1%5D=0, x%5B2%5D=0, and x%5B1%5D=-3


m=%28-3%29%2F%280--3%29 Subtract 0 from -3 to get -3


m=%28-3%29%2F%283%29 Subtract -3 from 0 to get 3


m=-1 Reduce


So the slope of the line that goes through the points and is m=-1


Now let's use the point slope formula:


y-y%5B1%5D=m%28x-x%5B1%5D%29 Start with the point slope formula


y-0=-1%28x--3%29 Plug in m=-1, x%5B1%5D=-3, and y%5B1%5D=0


y-0=-1%28x%2B3%29 Rewrite x--3 as x%2B3


y-0=-1x%2B-1%283%29 Distribute


y-0=-1x-3 Multiply


y=-1x-3%2B0 Add 0 to both sides.


y=-1x-3 Combine like terms.


y=-x-3 Simplify


So the equation that goes through the points and is y=-x-3


Notice how the graph of y=-x-3 goes through the points and . So this visually verifies our answer.
Graph of y=-x-3 through the points and