slope formula
m = y₂- y₁/ x₂- x₁
Ordered Pairs
(- 7, 2)(1, 6)
m = 6 - 2 / 1 - ( - 7)
m = 4 / 1 + 8
m = 4 / 8
m = 1/2
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Slope intercept form
y = mx + b
Ordered Pair
(- 7, 2)
2 = 1/2(- 7) + b
2 = - 7/2 + b
Transpose 7/2
2 + 7/2 = - 7/2 + b + 7/2
4/2 + 7/2 = b
Add the numerator
11/2 = b
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The equation
y = 1/2x + 11/2
Multiply both sides of the eqution by 2
2y = 2(1/2x) + 2(11/2)
2y = x + 11
Transpose x
- x + 2y = x + 11 - x
- x + 2y = 11
Transpose 11
- x + 2y - 11= 11 - 11
- x + 2y - 11 = 0
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2007-08-12 10:34:48
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answer #1
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answered by SAMUEL D 7
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Tou have only two points, therefore the equation will represent a straight line.
The "standard" form (or general form) of the equation is:
y = mx + c
where m is the "slope" (by how much does y increase when x increases by 1?) and c is the "intercept" (where does the line cross the y axis?).
The slope can be found by finding the change in y for the corresponding change in x.
Each point is given in the form (x, y).
You have:
(-7, 2) and (1, 6)
It does not matter in what order you do this, as long as you keep the same order for both variables:
x goes from -7 to +1, a change of +8
y goes from +2 to +6, a change of +4
The rate of change of y, in relation to x, is 4/8 = 1/2
Therefore m = 1/2 (or 0.5)
y = 0.5 x + c
We can use the values of the known points for x and y. Let's use (x, y) = (1,6)
6 = 0.5*1 + c
6 = 0.5 + c
6 - 0.5 = c
5.5 = c
y = 0.5 x + 5.5
Let's check with the other point (x, y) = (-7, 2)
2 ?=? 0.5*(-7) + 5.5
2 ?=? -3.5 + 5.5
2 ?=? 2
TRUE
(I wrote ?=? because we were checking if the equality was true; we did not know yet).
2007-08-12 16:35:26
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answer #2
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answered by Raymond 7
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Equation of the line thru the points (-7,2) and (1,6)
slope of the line, m = (6 - 2) / ( 1 - (-7))
= 4/8 = 1/2
(y - 6) / (x - 1) = m = 1/2
y - 6 = (1/2)(x - 1)
2(y - 6) = x -1
2y - 12 = x - 1
2y - x - 11 = 0
2007-08-12 16:28:45
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answer #3
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answered by vlee1225 6
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i know how u feel im 16 and i hate chem, AND math i suckd at it so bad... thanks god my chem teacher loved , she was awsome...lol but my math teacher failed me!! i had summer school this summer 250dollars!!! i hate her!!!
2007-08-12 16:29:51
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answer #4
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answered by Anonymous
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(y-y1)/(x-x1)=(y2-y1)/(x2-x1)
(y-2)/(x+7)=(6-2)/(1+7)
(y-2)/(x+7)=4/8=1/2
2y-4=x+7
2y-x=11
2007-08-12 16:29:22
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answer #5
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answered by Anonymous
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