SOLUTION: how do you write the equation lines through the given points? (2,4) (5,7)

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Question 117466This question is from textbook
: how do you write the equation lines through the given points?
(2,4) (5,7)
This question is from textbook

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
First lets find the slope through the points (2,4) and (5,7)

m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 Start with the slope formula (note: is the first point (2,4) and is the second point (5,7))

m=%287-4%29%2F%285-2%29 Plug in y%5B2%5D=7,y%5B1%5D=4,x%5B2%5D=5,x%5B1%5D=2 (these are the coordinates of given points)

m=+3%2F3 Subtract the terms in the numerator 7-4 to get 3. Subtract the terms in the denominator 5-2 to get 3


m=1 Reduce

So the slope is
m=1

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Now let's use the point-slope formula to find the equation of the line:



------Point-Slope Formula------
y-y%5B1%5D=m%28x-x%5B1%5D%29 where m is the slope, and is one of the given points

So lets use the Point-Slope Formula to find the equation of the line

y-4=%281%29%28x-2%29 Plug in m=1, x%5B1%5D=2, and y%5B1%5D=4 (these values are given)


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

y-4=1x-2 Multiply 1 and -2 to get -2

y=1x-2%2B4 Add 4 to both sides to isolate y

y=1x%2B2 Combine like terms -2 and 4 to get 2
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Answer:


So the equation of the line which goes through the points (2,4) and (5,7) is:y=1x%2B2

The equation is now in y=mx%2Bb form (which is slope-intercept form) where the slope is m=1 and the y-intercept is b=2

Notice if we graph the equation y=1x%2B2 and plot the points (2,4) and (5,7), we get this: (note: if you need help with graphing, check out this solver)

Graph of y=1x%2B2 through the points (2,4) and (5,7)

Notice how the two points lie on the line. This graphically verifies our answer.