Question

Question 4 (1 point)

Which of the following lines is perpendicular to y = 2x - 1?
a
b
x + 2y = 8
2x + y = 4
2x - y = 1
x - 2y = 6

Answer 1

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Answer:

x + 2y = 8

Explanation:

All of the answer choices are in standard form, so it is convenient for comparison to put the given line in standard form. Adding 1-y to both sides, we get ...

2x -y = 1

The perpendicular line will have a slope that is the negative reciprocal of the slope of this line. Effectively, that means the coefficients of x and y will be swapped, and one of them negated. That will give you ...

x +2y = 1

Any line with these x- and y-coefficients will be parallel, hence also perpendicular to the given line. The appropriate choice is ...

x + 2y = 8 . . . . the first choice