Question

Let c be any constant number. Which of the following will always be perpendicular to −3x + y = −1?

Answer 1

What are the options?

Answer 2

y equals one over three times x plus c

y equals negative one over three times x plus c

y equals negative three x plus c

y equals three x plus c

Answer 3

Two perpendicular lines (neither horizontal or vertical) have slopes that multiply to -1.
The given line −3x + y = −1 has a slope of 3. Place in y = mx + b form to get y = 3x -1. Look for a choice that has -1/3 as its slope.

y equals negative one over three times x plus c
which is y = (-1/3) (x) + c.