SOLUTION: i need help finding in slope intercept form through the points of (-3,1) and (5,4) I know i use y-y2 and x-x2 and then use y=mx+b , but i am stuck, thanks

Algebra ->  Linear-equations -> SOLUTION: i need help finding in slope intercept form through the points of (-3,1) and (5,4) I know i use y-y2 and x-x2 and then use y=mx+b , but i am stuck, thanks      Log On


   

Question 318569: i need help finding in slope intercept form through the points of (-3,1) and (5,4) I know i use y-y2 and x-x2 and then use y=mx+b , but i am stuck, thanks
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=-3 and y%5B1%5D=1.
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=%284-1%29%2F%285--3%29 Plug in y%5B2%5D=4, y%5B1%5D=1, x%5B2%5D=5, and x%5B1%5D=-3


m=%283%29%2F%285--3%29 Subtract 1 from 4 to get 3


m=%283%29%2F%288%29 Subtract -3 from 5 to get 8


So the slope of the line that goes through the points and is m=3%2F8


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-1=%283%2F8%29%28x--3%29 Plug in m=3%2F8, x%5B1%5D=-3, and y%5B1%5D=1


y-1=%283%2F8%29%28x%2B3%29 Rewrite x--3 as x%2B3


y-1=%283%2F8%29x%2B%283%2F8%29%283%29 Distribute


y-1=%283%2F8%29x%2B9%2F8 Multiply


y=%283%2F8%29x%2B9%2F8%2B1 Add 1 to both sides.


y=%283%2F8%29x%2B17%2F8 Combine like terms.


So the equation that goes through the points and is y=%283%2F8%29x%2B17%2F8