SOLUTION: Find the equation of the line that passes through the points (3, -2) and (4, -2).

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Question 133143: Find the equation of the line that passes through the points (3, -2) and (4, -2).

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 (3,-2) and (4,-2)

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 (4,-2))

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

m=+0%2F1 Subtract the terms in the numerator -2--2 to get 0. Subtract the terms in the denominator 4-3 to get 1


m=0 Reduce

So the slope is
m=0

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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=%280%29%28x-3%29 Plug in m=0, x%5B1%5D=3, and y%5B1%5D=-2 (these values are given)


y%2B2=%280%29%28x-3%29 Rewrite y--2 as y%2B2


y%2B2=0x%2B%280%29%28-3%29 Distribute 0

y%2B2=0x%2B0 Multiply 0 and -3 to get 0%2F0. Now reduce 0%2F0 to get 0

y=0x%2B0-2 Subtract 2 from both sides to isolate y

y=-2 Combine like terms 0 and -2 to get -2
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Answer:


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

The equation is now in y=mx%2Bb form (which is slope-intercept form) where the slope is m=0 and the y-intercept is b=-2

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

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

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