SOLUTION: Given 2 points (9,8) and (11,12), find the slope and write the equation of the line

Algebra ->  Graphs -> SOLUTION: Given 2 points (9,8) and (11,12), find the slope and write the equation of the line      Log On


   

Question 702847: Given 2 points (9,8) and (11,12), find the slope and write the equation of the line
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=9 and y%5B1%5D=8.
Also, is the second point . So this means that x%5B2%5D=11 and y%5B2%5D=12.


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


m=%2812-8%29%2F%2811-9%29 Plug in y%5B2%5D=12, y%5B1%5D=8, x%5B2%5D=11, and x%5B1%5D=9


m=%284%29%2F%2811-9%29 Subtract 8 from 12 to get 4


m=%284%29%2F%282%29 Subtract 9 from 11 to get 2


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-8=2%28x-9%29 Plug in m=2, x%5B1%5D=9, and y%5B1%5D=8


y-8=2x%2B2%28-9%29 Distribute


y-8=2x-18 Multiply


y=2x-18%2B8 Add 8 to both sides.


y=2x-10 Combine like terms.


So the equation that goes through the points and is y=2x-10