SOLUTION: What is the equation of a line with a slope of -5 and containing the point (2,4)?

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Question 92561: What is the equation of a line with a slope of -5 and containing the point (2,4)?
Found 2 solutions by ankor@dixie-net.com, jim_thompson5910:
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
What is the equation of a line with a slope of -5 and containing the point (2,4):
:
use the point/slope formula: (y - y1) = m(x - x1)
:
In your problem m = -5, x1=2; y1=4, so substitute and you have:
y - 4 = -5(x - 2)
:
y - 4 = -5x -5(-2);multiplied what's inside the brackets,
:
y - 4 = -5x + 10; minus * minus = +
:
y = -5x +10 + 4; add 4 to both sides
:
y = -5x + 14, is the equation

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

If you want to find the equation of line with a given a slope of -5 which goes through the point (2,4), you can simply use the point-slope formula to find the equation:


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

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

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


y-4=-5x%2B%28-5%29%28-2%29 Distribute -5

y-4=-5x%2B10 Multiply -5 and -2 to get 10

y=-5x%2B10%2B4 Add 4 to both sides to isolate y

y=-5x%2B14 Combine like terms 10 and 4 to get 14
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Answer:


So the equation of the line with a slope of -5 which goes through the point (2,4) is:

y=-5x%2B14 which is now in y=mx%2Bb form where the slope is m=-5 and the y-intercept is b=14

Notice if we graph the equation y=-5x%2B14 and plot the point (2,4), we get (note: if you need help with graphing, check out this solver)

Graph of y=-5x%2B14 through the point (2,4)
and we can see that the point lies on the line. Since we know the equation has a slope of -5 and goes through the point (2,4), this verifies our answer.