Answer: -2x+3y = 21 which is choice C
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Work Shown:
The slope of the original line is -3/2. The perpendicular slope is 2/3. We flip the fraction and flip the sign. Multiplying the original slope (-3/2) and the perpendicular slope (2/3) will result in -1. Let's use this perpendicular slope and the point to find the equation of the perpendicular line in slope intercept form.
y = m+b
y = (2/3)x+b .... plug in the perpendicular slope
9 = (2/3)(3)+b .... plug in the point (x,y) = (3,9)
9 = 2+b
9-2 = 2+b-2 ... subtract 2 from both sides
b = 7
So y = (2/3)x+b turns into y = (2/3)x+7.
This equation is in slope intercept form.
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Let's convert to standard form
y = (2/3)x+7
3*y = 3*((2/3)x+7) ... multiply both sides by 3 to clear out the fraction
3*y = 3*(2/3)x+3*7 ... distribute
3y = 2x+21
-2x+3y = 21 .... get the x term to the other side (subtract 2x from both sides)