Question 159320: find point-slope equation of the line through each pair of points.
1. (7,5) and (3,9)
2. (-4,1) and (6,5)
3. (6,-5) and (-2,-17)
4 (2/3,-6) and (4/3,-5)
question is from my homework.
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! find point-slope equation of the line through each pair of points.
1. (7,5) and (3,9)
2. (-4,1) and (6,5)
3. (6,-5) and (-2,-17)
4 (2/3,-6) and (4/3,-5)
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I'll do 1 and 4 to show you how.
Slope m = (y2-y1)/(x2-x1)
1. m = (7-3)/(5-9)
= 4/-4
= -1
To find the eqn, use the slope and either point in the slope-intercept eqn,
y = mx + b
y-y1 = m(x-x1) Ignore the b for this part
y-5 = -1*(x-7)
y-5 = -x + 7
y = -x + 2 (slope-intercept form of eqn)
x + y = 2 (standard form)
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4. (2/3,-6) and (4/3,-5)
Slope m = (y2-y1)/(x2-x1)
m = (-5 - (-6))/(4/3 - 2/3)
m = 1/(2/3)
m = 3/2, or 1.5
Use point 1.
y-y1 = m*(x-x1)
y-(-6) = 1.5*(x - 2/3)
y + 6 = 1.5x - 1
y = 1.5x -7 (slope-intercept form)
3x - 2y = 14 (standard form)
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