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Find w, given that the line joining a(3,4) to b(w,-5) is perpendicular to a line with slope -2/3

User DougW
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1 Answer

5 votes

Answer:

w is -3

Explanation:

A line with a perpendicular slope with have a slope that is the negative inverse of the reference line. If the reference line is -(2/3), the perpendicular line will have a slope of (3/2).

The line formed by ab: y = (3/2)x + b

We have one given point on line ab with one coordinate known, (3,4), so let's use it to find b:

y = (3/2)x + b

4 = (3/2)*3 + b for (3,4)

4 = (9/2) + b

b = 4 - (9/2)

b = - 0.5

The equation is y = (3/2)x - 0.5

The slope of (3/2) is equal to the Rise/Run of two points on the line: (3,4) and (w,-5):

Rise = (4 - (-5)) = 9

Run = (3 - w)

Slope = 9/(3-w)

(3/2) = 9/(3-w)

(3/2)(3-w) = 9

(9/2) - (3/2)w = 9

9 - 3w = 18

-3w = 9

w = -3

Point b is (-3, -5)

See attached graph.

Find w, given that the line joining a(3,4) to b(w,-5) is perpendicular to a line with-example-1
User Sukesh
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4.7k points