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Question 497730: write an equation of the line that passes through the points (5,2) and (2,8)
Found 2 solutions by Alan3354, lwsshak3:
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! write an equation of the line that passes through the points (5,2) and (2,8)
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|x y 1|
|5 2 1| = 0
|2 8 1|
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x(2-8) - y(5-2) + (40-4) = 0
-6x - 3y = -36
2x + y = 12 Standard form
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The hard way:
Find the slope, m
m = diffy/diffx
m = (2-8)/(5-2) = -6/3
m = -2
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Use y = mx+b and either point to find b
8 = -2*2 + b
b = 12
y = -2x + 12 slope-intercept form, same answer
Answer by lwsshak3(11628)  (Show Source):
You can put this solution on YOUR website! write an equation of the line that passes through the points (5,2) and (2,8)
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Standard form of an equation for a straight line: y=mx+b, m=slope, b=y-intercept
For given problem:
slope=∆y/∆x=(8-2)/(2-5)=6/-3=-2
Equation: y=-2x+b
Find y-intercept b using one of given points (5,2)
2=-2*5+b
2=-10+b
b=12
Equation: y=-2x+12
See graph below as a visual check on answer:
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