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Consider the following equation

3x + 9y = 8y - 2

Step 2 of 2: Find the equation of the line which passes through the point (13,5) and is perpendicular to the given line. Express your answer in
slope-intercept form. Simplify your answer.

User Parnell
by
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1 Answer

4 votes

Answer:

The perpendicular line is:

y = 1/3 x + 2/3

Explanation:

The given equation can be reduced to its slope-intercept form as shown below:

3x + 9y = 8y - 2

subtract 8 y from both sides

3 x + y = -2

subtract 3 x from both sides

y = - 3 x -2

therefore we know that the slope of this line is -3, and then, a perpendicular line to it must have slope given by the "opposite of the reciprocal" of this slope. That is, the slope of any perpendicular line to this one must be: 1/3

We use this slope to find the equation of the line passing through the point (13. 5)

y = 1/3 x + b

passing through (13, 5) means:

5 = 1/3 (13) + b

therefore, we can find b from the above equation

b = 5 - 13/3 = 15/3 - 13/3 = 2/3

Then the equation of this perpendicular line is:

y = 1/3 x + 2/3

User Chad Portman
by
3.3k points