SOLUTION: Find an equation of the line contaiing the given pair of points. Express your answer in the form x=a, y=b, or y=mx=b. (-1,-1) and (4,4) What is an equation of the line? y

Algebra ->  Graphs -> SOLUTION: Find an equation of the line contaiing the given pair of points. Express your answer in the form x=a, y=b, or y=mx=b. (-1,-1) and (4,4) What is an equation of the line? y      Log On


   

Question 160008: Find an equation of the line contaiing the given pair of points. Express your answer in the form x=a, y=b, or y=mx=b.
(-1,-1) and (4,4)
What is an equation of the line?
y= _____
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


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%284--1%29 Plug in y%5B2%5D=4, y%5B1%5D=-1, x%5B2%5D=4, and x%5B1%5D=-1


m=%285%29%2F%284--1%29 Subtract -1 from 4 to get 5


m=%285%29%2F%285%29 Subtract -1 from 4 to get 5


m=1 Reduce


So the slope of the line that goes through the points and is m=1


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


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


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


y%2B1=1x%2B1%281%29 Distribute


y%2B1=1x%2B1 Multiply


y=1x%2B1-1 Subtract 1 from both sides.


y=1x%2B0 Combine like terms.


y=1x Remove the trailing zero


y=x Simplify


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


Notice how the graph of y=x goes through the points and . So this visually verifies our answer.
Graph of y=x through the points and