##### Find slope of two points

label Algebra
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schedule 1 Day
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Write an equation for two points on a line of a graph. (0, -2) (-2,-6)

Oct 22nd, 2015

So the standard equation of a line is y = mx + b where m is slope, and b is the y-intercept

To find the slope of the line you use the equation (y2 - y1) / (x2 - x1) where (0, -2) is (x1, y1) and (-2, -6) is (x2, y2).

So first you subtract: (-6 - -2) since two negatives make a positive it's (-6 +2) which is -4

Then you subtract the x's: (-2 - 0) which is just -2

Now that you have the numbers you divide: -4/-2 Dividing with two negative numbers makes a positive so you get +2 or just 2. That is the slope of the line or m.

so now you have y = 2x + b

To find the b value you plug one of the points into the equation for y and x. Using (0, -2) where 0 is x and -2 is y we get: -2 = 2(0) + b .. Since 2 x 0 is 0, then b is equal to -2. So your final line equation is

y = 2x -2

Oct 22nd, 2015

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Oct 22nd, 2015
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Oct 22nd, 2015
Oct 21st, 2017
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