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31 votes
Write an equation of a line

passing through the point
(-1, 3) and parallel to AB with
A(3, -5) and B(-2, 15).
A) y = -4x - 1
B) y = -4x + 7
C) y = -4x - 3
D) y = 1/4x + 5
E) y = 1/4x – 8

User Yris
by
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1 Answer

11 votes
11 votes

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Answer:

A) y = -4x -1

Explanation:

Trying the given point in the offered equations quickly tells you that the correct choice is ...

y = -4x -1

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In the first equation, (x, y) = (-1, 3) gives ...

3 = -4(-1) -1= 4 -1 . . . . true

The remaining equations cannot give this same result, so equation A is the correct choice.

_____

Additional comment

If you want to write your own equation, the slope would be ...

m = (y2 -y1)/(x2 -x1) . . . . from the points on the parallel line

m = (15 -(-5))/(-2 -3) = 20/-5 = -4

The y-intercept would be ...

b = y -mx . . . . from the given point

b = 3 -(-4)(-1) = 3 -4 = -1

Then the slope-intercept equation is ...

y = mx +b

y = -4x -1

Write an equation of a line passing through the point (-1, 3) and parallel to AB with-example-1