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Find the equation of the line.
Use exact numbers!!!!!!!

Find the equation of the line. Use exact numbers!!!!!!!-example-1

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The equation of a line format is y=mx + c, m being the gradient and c being the y intercept, so you have to find both of those.

1) Find the gradient of the line.
The formula for this is: the change in y divided by the change in x.

Pick 2 points on the line that have exact co-ordinates. I picked 2 points that have the co-ordinates (-8,-8) and (8,4), but you can pick any 2 points and get the same answer.
Find the difference of the x points and y points:

change in x: 8-(-8)=16
change in y: 4-(-8)=12

divide the change in y by the change in x.
12/16= 3/4
The gradient is 3/4.

2) Find the y intercept.
The equation of a line format is y= mx+c.
Pick any point whatsoever on the line, i’ll pick a point that has the coordinates (8,4), 4 being the y point and 8 being the x point.

y=mx +c
you know the gradient is 3/4, so:

4= 3/4 x 8 +c
4= 6+c
-2 =c

So the y intercept is -2.

3) Put it all into y= mx+c

y= 3/4-2 is (hopefully) the answer


(i may have made calculation mistakes and i apologise if i’m wrong, but i tried)
User StevieG
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