SOLUTION: algebra 2 write an equation for the line with the given info. pts (3,5) (5,12) I know that you have to use slope intercept for y=mx+b but i dont know how to find the slope. I th

Algebra ->  Graphs -> SOLUTION: algebra 2 write an equation for the line with the given info. pts (3,5) (5,12) I know that you have to use slope intercept for y=mx+b but i dont know how to find the slope. I th      Log On


   

Question 195588: algebra 2
write an equation for the line with the given info.
pts (3,5) (5,12)
I know that you have to use slope intercept for y=mx+b but i dont know how to find the slope. I think you have to make a graph but Im not sure.
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 and is the second point .


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


m=%2812-5%29%2F%285-3%29 Plug in y%5B2%5D=12, y%5B1%5D=5, x%5B2%5D=5, and x%5B1%5D=3


m=%287%29%2F%285-3%29 Subtract 5 from 12 to get 7


m=%287%29%2F%282%29 Subtract 3 from 5 to get 2


So the slope of the line that goes through the points and is m=7%2F2


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-5=%287%2F2%29%28x-3%29 Plug in m=7%2F2, x%5B1%5D=3, and y%5B1%5D=5


y-5=%287%2F2%29x%2B%287%2F2%29%28-3%29 Distribute


y-5=%287%2F2%29x-21%2F2 Multiply


y=%287%2F2%29x-21%2F2%2B5 Add 5 to both sides.


y=%287%2F2%29x-11%2F2 Combine like terms.


So the equation that goes through the points and is y=%287%2F2%29x-11%2F2