SOLUTION: find the equation of the following lines, write the answer in slop-intercept form. through (7,10) and (-1,-1)

Algebra ->  Linear-equations -> SOLUTION: find the equation of the following lines, write the answer in slop-intercept form. through (7,10) and (-1,-1)      Log On


   

Question 221024: find the equation of the following lines, write the answer in slop-intercept form.
through (7,10) and (-1,-1)
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=7 and y%5B1%5D=10.
Also, is the second point . So this means that x%5B2%5D=-1 and y%5B2%5D=-1.


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


m=%28-1-10%29%2F%28-1-7%29 Plug in y%5B2%5D=-1, y%5B1%5D=10, x%5B2%5D=-1, and x%5B1%5D=7


m=%28-11%29%2F%28-1-7%29 Subtract 10 from -1 to get -11


m=%28-11%29%2F%28-8%29 Subtract 7 from -1 to get -8


m=11%2F8 Reduce


So the slope of the line that goes through the points and is m=11%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-10=%2811%2F8%29%28x-7%29 Plug in m=11%2F8, x%5B1%5D=7, and y%5B1%5D=10


y-10=%2811%2F8%29x%2B%2811%2F8%29%28-7%29 Distribute


y-10=%2811%2F8%29x-77%2F8 Multiply


y=%2811%2F8%29x-77%2F8%2B10 Add 10 to both sides.


y=%2811%2F8%29x%2B3%2F8 Combine like terms.


So the equation that goes through the points and is y=%2811%2F8%29x%2B3%2F8