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1 vote
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Which pair of lines
are parallel?
A) x − 5y = 10; y = 5x – 2
B) x + y = 0; y = x + 7
C) 2x - 3y = 9; 4y = 6x-20
D) 4x8y = 8; y = 2x + 2
E) 9x - 3y = 12; y = 3x - 10

User Juank
by
7.2k points

1 Answer

2 votes

Explanation:

To determine whether two lines are parallel, we need to compare their slopes. If the slopes are equal, then the lines are parallel.

The slope-intercept form of a linear equation is y = mx + b, where m is the slope and b is the y-intercept.

A) x − 5y = 10 can be rearranged to y = (1/5)x − 2, so its slope is 1/5.

y = 5x – 2 is already in slope-intercept form, so its slope is 5.

These two slopes are not equal, so the lines are not parallel.

B) x + y = 0 can be rearranged to y = −x, so its slope is −1.

y = x + 7 is already in slope-intercept form, so its slope is 1.

These two slopes are not equal, so the lines are not parallel.

C) 2x − 3y = 9 can be rearranged to y = (2/3)x − 3, so its slope is 2/3.

4y = 6x − 20 can be rearranged to y = (3/2)x − 5, so its slope is 3/2.

These two slopes are not equal, so the lines are not parallel.

D) 4x + 8y = 8 can be rearranged to y = −(1/2)x + 1, so its slope is −1/2.

y = 2x + 2 is already in slope-intercept form, so its slope is 2.

These two slopes are not equal, so the lines are not parallel.

E) 9x − 3y = 12 can be rearranged to y = 3x − 4, so its slope is 3.

y = 3x − 10 is already in slope-intercept form, so its slope is 3.

These two slopes are equal, so the lines are parallel.

Therefore, the pair of lines that are parallel is (E) 9x - 3y = 12; y = 3x - 10.

User Mark Horgan
by
7.3k points