SOLUTION: (2,-3) (-5,4) find the slope , show the linear equation, draw a graph

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Question 140258: (2,-3)
(-5,4)

find the slope , show the linear equation, draw a graph

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,-3) and (-5,4)

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,-3) and is the second point (-5,4))

m=%284--3%29%2F%28-5-2%29 Plug in y%5B2%5D=4,y%5B1%5D=-3,x%5B2%5D=-5,x%5B1%5D=2 (these are the coordinates of given points)

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


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--3=%28-1%29%28x-2%29 Plug in m=-1, x%5B1%5D=2, and y%5B1%5D=-3 (these values are given)


y%2B3=%28-1%29%28x-2%29 Rewrite y--3 as y%2B3


y%2B3=-x%2B%28-1%29%28-2%29 Distribute -1

y%2B3=-x%2B2 Multiply -1 and -2 to get 2

y=-x%2B2-3 Subtract 3 from both sides to isolate y

y=-x-1 Combine like terms 2 and -3 to get -1
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Answer:


So the equation of the line which goes through the points (2,-3) and (-5,4) is:y=-x-1

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=-1

Notice if we graph the equation y=-x-1 and plot the points (2,-3) and (-5,4), we get this: (note: if you need help with graphing, check out this solver)

Graph of y=-x-1 through the points (2,-3) and (-5,4)

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