Question 249107
Write an equation of the line that passes through the point (-3,-1) and is perpendicular to the line x + 3y = 9. 
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Find the slope of the given line:
3y = -x + 9
y = (-1/3)x + 3
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Slope of the given line is -1/3.
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Note: Any line perpendicular to the given line must have slope -3.
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Your Problem:
You want the equation of the line that has slope -3 and passes thru (-3,-1).
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Form of the line is y = mx + b; you need to find "m" and "b":
m = -3
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-1 = -3*-3 + b
-1 = 9 + b
b = -10
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Equation:
y = -3x - 10
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Cheers,
Stan H.