SOLUTION: write the equation of the line passing through the points (8,-39) and (1,3)

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Question 750887: write the equation of the line passing through the points (8,-39) and (1,3)
Found 2 solutions by jim_thompson5910, stanbon:
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=8 and y%5B1%5D=-39.
Also, is the second point . So this means that x%5B2%5D=1 and y%5B2%5D=3.


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


m=%283--39%29%2F%281-8%29 Plug in y%5B2%5D=3, y%5B1%5D=-39, x%5B2%5D=1, and x%5B1%5D=8


m=%2842%29%2F%281-8%29 Subtract -39 from 3 to get 42


m=%2842%29%2F%28-7%29 Subtract 8 from 1 to get -7


m=-6 Reduce


So the slope of the line that goes through the points and is m=-6


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--39=-6%28x-8%29 Plug in m=-6, x%5B1%5D=8, and y%5B1%5D=-39


y%2B39=-6%28x-8%29 Rewrite y--39 as y%2B39


y%2B39=-6x%2B-6%28-8%29 Distribute


y%2B39=-6x%2B48 Multiply


y=-6x%2B48-39 Subtract 39 from both sides.


y=-6x%2B9 Combine like terms.


So the equation that goes through the points and is y=-6x%2B9


Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
write the equation of the line passing through the points (8,-39) and (1,3)
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slope = (3--39)/(1-8) = 42/-7 = -6
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Form: y = mx + b
3 = -6*1 + b
b = 9
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Equation:
y = -6x + 9
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Cheers,
Stan H.