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Question 482238: what equation would go through the points (-2,1)(2,-1)
Found 2 solutions by Alan3354, MathLover1:
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! Use determinants:
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|+x +y +1|
|-2 +1 +1| = 0
|+2 -1 +1|
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x(1+1) - y(-2-2) + (2-2) = 0
2x + 4y = 0
x + 2y = 0
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Without determinants:
Find the slope, m = diffy/diffx
m = -2/4 = -1/2
Use y = mx+b and either point to find b. I'll use (2,-1)
-1 = (-1/2)*2 + b
b = 0
y = (-1/2)x
y = -x/2
x + 2y = 0
Answer by MathLover1(20850)  (Show Source):
You can put this solution on YOUR website!
| Solved by pluggable solver: FIND EQUATION of straight line given 2 points |
hahaWe are trying to find equation of form y=ax+b, where a is slope, and b is intercept, which passes through points (x1, y1) = (-2, 1) and (x2, y2) = (2, -1).
Slope a is  .
Intercept is found from equation  , or  . From that,
intercept b is  , or  .
y=(-0.5)x + (0)
Your graph:
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