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Help! It says that I need to determine If both equations represent lines which are parallel, perpendicular, or none...

And then they give me two equations like
4x + 2y = 8
8x + 4y = -4y

User Sean Hogan
by
7.9k points

1 Answer

5 votes
4x + 2y = 8 (1)
8x + 4y = -4y (2)

A) Two lines are parallel if they have the same gradient
- putting both equations into the gradient- intercept form ( y = mx + c where m is the gradient)
(1) 4x + 2y = 8
2y = 8 - 4x
y = -2x + 4

(2) 8x + 4y = -4y
8x = -4y - 4y
y =
(-8x)/(-8)
y = -x
Thus the gradient of the two equations are different and as such the two lines are not parallel

B) When two lines are perpendicular, the product of their gradient is -1

m_(1) * m_(2) = p
p = (-2) * (-1)
p = 2
the two lines are not perpendicular either.

Thus these lines are SKEWED LINES

User Anabel
by
7.4k points

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