
Home > AC > Chapter 7 > Lesson 7.3.3 > Problem 7-110
Find the slope of each line below. Which pairs of lines are perpendicular? Which pairs are parallel? Homework Help ✎
y =
+ 3
y = 3
5x + 6y = 9
x = −4
y = −4x − 5
y =
− 7
4x − y = 2
y = 5 −
Slopes that are opposite reciprocals of each other are perpendicular, while parallel lines share the same slope.
Slope is given in the equation.
y = 3 is a horizontal line, thus its slope is zero.
Rearrange the equation into the y = mx + b form to identify the slope.
x = −4 is a vertical line, thus its slope is undefined.
Slope is given.
Slope is given.
Rearrange the equation into the y = mx + b form to identify the slope.
Rearrange slightly and identify the slope.
An example of a pair of parallel lines is the line from part (a) and the line from part (c), while an example of a pair of perpendicular
lines is the line from part (b) and the line from part (d). Knowing this information, can you find your own examples?