SOLUTION: Find an equation of the line containing the given pair of points. (4,1) and (12,3)

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Question 189702: Find an equation of the line containing the given pair of points. (4,1) and (12,3)
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=%283-1%29%2F%2812-4%29 Plug in y%5B2%5D=3, y%5B1%5D=1, x%5B2%5D=12, and x%5B1%5D=4


m=%282%29%2F%2812-4%29 Subtract 1 from 3 to get 2


m=%282%29%2F%288%29 Subtract 4 from 12 to get 8


m=1%2F4 Reduce


So the slope of the line that goes through the points and is m=1%2F4


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=%281%2F4%29%28x-4%29 Plug in m=1%2F4, x%5B1%5D=4, and y%5B1%5D=1


y-1=%281%2F4%29x%2B%281%2F4%29%28-4%29 Distribute


y-1=%281%2F4%29x-1 Multiply


y=%281%2F4%29x-1%2B1 Add 1 to both sides.


y=%281%2F4%29x%2B0 Combine like terms.


y=%281%2F4%29x Remove the trailing zero



So the equation that goes through the points and is y=%281%2F4%29x


Notice how the graph of y=%281%2F4%29x goes through the points and . So this visually verifies our answer.
Graph of y=%281%2F4%29x through the points and