SOLUTION: Write the equation of the line through (-1,0) and (1,2) in slope intercept form

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Question 670799: Write the equation of the line through (-1,0) and (1,2) in slope intercept form
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 . So this means that x%5B1%5D=-1 and y%5B1%5D=0.
Also, is the second point . So this means that x%5B2%5D=1 and y%5B2%5D=2.


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


m=%282-0%29%2F%281--1%29 Plug in y%5B2%5D=2, y%5B1%5D=0, x%5B2%5D=1, and x%5B1%5D=-1


m=%282%29%2F%281--1%29 Subtract 0 from 2 to get 2


m=%282%29%2F%282%29 Subtract -1 from 1 to get 2


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


y-0=1%28x%2B1%29 Rewrite x--1 as x%2B1


y-0=1x%2B1%281%29 Distribute


y-0=1x%2B1 Multiply


y=1x%2B1%2B0 Add 0 to both sides.


y=1x%2B1 Combine like terms.


y=x%2B1 Simplify


So the equation that goes through the points and is y=x%2B1


Notice how the graph of y=x%2B1 goes through the points and . So this visually verifies our answer.
Graph of y=x%2B1 through the points and