SOLUTION: Find the equation of the line containing the given pair of points (-1,-9) and (-5,-4)

Algebra ->  Functions -> SOLUTION: Find the equation of the line containing the given pair of points (-1,-9) and (-5,-4)      Log On


   

Question 612454: Find the equation of the line containing the given pair of points (-1,-9) and (-5,-4)
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=-9.
Also, is the second point . So this means that x%5B2%5D=-5 and y%5B2%5D=-4.


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


m=%28-4--9%29%2F%28-5--1%29 Plug in y%5B2%5D=-4, y%5B1%5D=-9, x%5B2%5D=-5, and x%5B1%5D=-1


m=%285%29%2F%28-5--1%29 Subtract -9 from -4 to get 5


m=%285%29%2F%28-4%29 Subtract -1 from -5 to get -4


m=-5%2F4 Reduce


So the slope of the line that goes through the points and is m=-5%2F4


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--9=%28-5%2F4%29%28x--1%29 Plug in m=-5%2F4, x%5B1%5D=-1, and y%5B1%5D=-9


y--9=%28-5%2F4%29%28x%2B1%29 Rewrite x--1 as x%2B1


y%2B9=%28-5%2F4%29%28x%2B1%29 Rewrite y--9 as y%2B9


y%2B9=%28-5%2F4%29x%2B%28-5%2F4%29%281%29 Distribute


y%2B9=%28-5%2F4%29x-5%2F4 Multiply


y=%28-5%2F4%29x-5%2F4-9 Subtract 9 from both sides.


y=%28-5%2F4%29x-41%2F4 Combine like terms. note: If you need help with fractions, check out this solver.


So the equation that goes through the points and is y=%28-5%2F4%29x-41%2F4

--------------------------------------------------------------------------------------------------------------
If you need more help, email me at jim_thompson5910@hotmail.com

Also, please consider visiting my website: http://www.freewebs.com/jimthompson5910/home.html and making a donation. Thank you

Jim
--------------------------------------------------------------------------------------------------------------