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Write an equation of the line that passes through the given points.

​(-1​,5​) and ​(2​,-7​)

Pls i need help for the question

User Atrotors
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2 Answers

5 votes
m = (-7-5)/(2+1) = -12/3 = -4
y = -4x + b
use one of the points
5 = -4 (-1) + b
5 = 4 + b
b = 1

y = -4x + 1
User Shrimpwagon
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5.6k points
6 votes

The slope intercept formula is:

y = mx + b

m is the slope

b is the y-intercept

Let's first find slope:

The formula for slope is


(y_(2)-y_(1))/(x_(2)-x_(1))

In this case we have the points (-1, 5) and (2, -7)


y_(2) =-7\\y_(1) =5\\x_(2) =2\\x_(1) =-1

^^^Plug these numbers into the formula for slope...


(-7-5)/(2-(-1))


(-12)/(3)

-4

^^^This is your slope

So far you have the equation:

y = -4x + b

Now we must find b

To do that you must plug in a point the line goes through in the x and y of the equation. This is the one I have chosen:

(-1, 5)

5 = -4(-1) + b

5 = 4 + b

1 = b

y = -4x + 1

Hope this helped!

~Just a girl in love with Shawn Mendes

User Rob Deary
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4.8k points