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21 votes
21 votes
Write an equation of the line that contains the point (3.-2) and is perpendicular to the line 3x - 6y = 7.

User Divided
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1 Answer

19 votes
19 votes

Answer:

y = -2x + 4

Explanation:

Perpendicular lines intersect at a point that form right angles; these lines also have negative reciprocal slopes, in which the product of their slopes result in a negative one (-1 ).

Given the linear equation in standard form, 3x - 6y = 7, and the point (3, -2):

Transform the standard form into slope-intercept form: y = mx + b

3x - 6y = 7

3x - 3x - 6y = -3x + 7

-6y = -3x + 7

Divide both sides by -6 to isolate y:


(-6y)/(-6) = (-3x + 7)/(-6)

y = ½x - 7/6 (This is the slope-intercept form of the given equation, 3x - 6y = 7).

Now that we have the slope of the given equation,
m_1 = ½, then we can determine that the slope of the other line must be
m_2 = -2:


m_1 ×
m_2 = ½ × -2 = -1

Next, using the slope of the other line,
m_2 = -2, and the given point, (3, -2), substitute these values into the slope-intercept form to solve for the value of the y-intercept, b:

y = mx + b

-2 = -2(3) + b

-2 = -6 + b

Add 6 to both sides to isolate b:

-2 + 6 = -6 + 6 + b

4 = b (This is the y-intercept of the other line).

Therefore, the linear equation of the line that is perpendicular to 3x - 6y = 7 is:

y = -2x + 4

User Daniel Centore
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2.5k points