SOLUTION: What is the equation of a line passing through (–7, 7) and (–6, 9) in slope-intercept form?

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Question 626101: What is the equation of a line passing through (–7, 7) and (–6, 9) 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=-7 and y%5B1%5D=7.
Also, is the second point . So this means that x%5B2%5D=-6 and y%5B2%5D=9.


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


m=%289-7%29%2F%28-6--7%29 Plug in y%5B2%5D=9, y%5B1%5D=7, x%5B2%5D=-6, and x%5B1%5D=-7


m=%282%29%2F%28-6--7%29 Subtract 7 from 9 to get 2


m=%282%29%2F%281%29 Subtract -7 from -6 to get 1


m=2 Reduce


So the slope of the line that goes through the points and is m=2


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-7=2%28x--7%29 Plug in m=2, x%5B1%5D=-7, and y%5B1%5D=7


y-7=2%28x%2B7%29 Rewrite x--7 as x%2B7


y-7=2x%2B2%287%29 Distribute


y-7=2x%2B14 Multiply


y=2x%2B14%2B7 Add 7 to both sides.


y=2x%2B21 Combine like terms.


So the equation that goes through the points and is y=2x%2B21


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