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What is the equation of a line that is perpendicular to the given line and has an x-intercept of 6?

User Rodriguez
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2 Answers

3 votes

Answer:

C.

Explanation:

Just took the test ;)

User CLo
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3 votes

Answer:

y = 4/3(x) - 8

Explanation:

First we have to find the equation for the given line (I use y = mx + b for everything, although I think it can be done with other formats). The equation for slope is (y2 - y1)/(x2 - x1) = m, so we'll start with that.

(-2 - 4) / (4 - (-4)) = m

-6 / 8 = m

m = -3/4

Now, let's find the rest of the equation. We can do this by treating b as the unknown variable it is, and plugging in a known xy pair, then simply solving for the unknown variable.

y = mx + b; y = 4, x = -4, m = -3/4

4 = -4(-3/4) + b

4 = 3 + b

b = 1

Now we have the original line's equation, y = -3/4(x) + 1. We need to find the new line's slope by finding the negative reciprocal of the base line's. For that, we simply flip the numerator and denominator, then multiply it by -1, to get 4/3. Now we find b again, using the point (6, 0).

y = mx + b; y = 0, x = 6, m = 4/3

0 = 4/3(6) + b

0 = 8 + b

b = -8

This makes our final answer y = 4/3(x) - 8.

User Tallowen
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