Question

When are two distinct nonvertical lines parallel?

a)

when the slopes are equal


b)

when the slopes are positive


c)

when the product of the slopes is –1


d)

when the slopes are opposite

Answer 1

a) when the slopes are equal

Explanation:

The slopes of lines can be used to define the nature of lines.

Two parallel lines have equal slopes and the product of slopes of perpendicular lines is -1.

Hence, we can conclude that two distinct non-vertical lines parallel when

a) when the slopes are equal ..

So, option a is correct ..