SOLUTION: (-3,-2),(5,4)

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Question 132918: (-3,-2),(5,4)
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Do you want to find the equation of the line through these points?



First lets find the slope through the points (-3,-2) 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 (-3,-2) and is the second point (5,4))

m=%284--2%29%2F%285--3%29 Plug in y%5B2%5D=4,y%5B1%5D=-2,x%5B2%5D=5,x%5B1%5D=-3 (these are the coordinates of given points)

m=+6%2F8 Subtract the terms in the numerator 4--2 to get 6. Subtract the terms in the denominator 5--3 to get 8


m=3%2F4 Reduce

So the slope is
m=3%2F4

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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--2=%283%2F4%29%28x--3%29 Plug in m=3%2F4, x%5B1%5D=-3, and y%5B1%5D=-2 (these values are given)


y%2B2=%283%2F4%29%28x--3%29 Rewrite y--2 as y%2B2


y%2B2=%283%2F4%29%28x%2B3%29 Rewrite x--3 as x%2B3


y%2B2=%283%2F4%29x%2B%283%2F4%29%283%29 Distribute 3%2F4

y%2B2=%283%2F4%29x%2B9%2F4 Multiply 3%2F4 and 3 to get 9%2F4

y=%283%2F4%29x%2B9%2F4-2 Subtract 2 from both sides to isolate y

y=%283%2F4%29x%2B1%2F4 Combine like terms 9%2F4 and -2 to get 1%2F4 (note: if you need help with combining fractions, check out this solver)


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Answer:


So the equation of the line which goes through the points (-3,-2) and (5,4) is:y=%283%2F4%29x%2B1%2F4

The equation is now in y=mx%2Bb form (which is slope-intercept form) where the slope is m=3%2F4 and the y-intercept is b=1%2F4

Notice if we graph the equation y=%283%2F4%29x%2B1%2F4 and plot the points (-3,-2) and (5,4), we get this: (note: if you need help with graphing, check out this solver)

Graph of y=%283%2F4%29x%2B1%2F4 through the points (-3,-2) and (5,4)

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