SOLUTION: Write the equation of the line passing through (6, –5) and (–3, 4)

Algebra ->  Coordinate-system -> SOLUTION: Write the equation of the line passing through (6, –5) and (–3, 4)      Log On


   



Question 113890: Write the equation of the line passing through (6, –5) and (–3, 4)
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 (6,-5) and (-3,4)

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

m=%284--5%29%2F%28-3-6%29 Plug in y%5B2%5D=4,y%5B1%5D=-5,x%5B2%5D=-3,x%5B1%5D=6 (these are the coordinates of given points)

m=+9%2F-9 Subtract the terms in the numerator 4--5 to get 9. Subtract the terms in the denominator -3-6 to get -9


m=-1 Reduce

So the slope is
m=-1

------------------------------------------------


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--5=%28-1%29%28x-6%29 Plug in m=-1, x%5B1%5D=6, and y%5B1%5D=-5 (these values are given)


y%2B5=%28-1%29%28x-6%29 Rewrite y--5 as y%2B5


y%2B5=-x%2B%28-1%29%28-6%29 Distribute -1

y%2B5=-x%2B6 Multiply -1 and -6 to get 6

y=-x%2B6-5 Subtract 5 from both sides to isolate y

y=-x%2B1 Combine like terms 6 and -5 to get 1
------------------------------------------------------------------------------------------------------------
Answer:


So the equation of the line which goes through the points (6,-5) and (-3,4) is:y=-x%2B1

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%2B1 and plot the points (6,-5) and (-3,4), we get this: (note: if you need help with graphing, check out this solver)

Graph of y=-x%2B1 through the points (6,-5) and (-3,4)

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