SOLUTION: Write the equation of a line in slope-intercept form that passes through (-1, 4) and (2, 0).

Algebra ->  Linear-equations -> SOLUTION: Write the equation of a line in slope-intercept form that passes through (-1, 4) and (2, 0).      Log On


   

Question 867583: Write the equation of a line in slope-intercept form that passes through (-1, 4) and (2, 0).
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=4.
Also, is the second point . So this means that x%5B2%5D=2 and y%5B2%5D=0.


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


m=%280-4%29%2F%282--1%29 Plug in y%5B2%5D=0, y%5B1%5D=4, x%5B2%5D=2, and x%5B1%5D=-1


m=%28-4%29%2F%282--1%29 Subtract 4 from 0 to get -4


m=%28-4%29%2F%283%29 Subtract -1 from 2 to get 3


So the slope of the line that goes through the points and is m=-4%2F3


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-4=%28-4%2F3%29%28x--1%29 Plug in m=-4%2F3, x%5B1%5D=-1, and y%5B1%5D=4


y-4=%28-4%2F3%29%28x%2B1%29 Rewrite x--1 as x%2B1


y-4=%28-4%2F3%29x%2B%28-4%2F3%29%281%29 Distribute


y-4=%28-4%2F3%29x-4%2F3 Multiply


y=%28-4%2F3%29x-4%2F3%2B4 Add 4 to both sides.


y=%28-4%2F3%29x%2B8%2F3 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=%28-4%2F3%29x%2B8%2F3