Find the slope of each line below. Which pairs of lines are perpendicular? Which pairs are parallel? Homework Help ✎
1. y = + 3
2. y = 3
3. 5x + 6y = 9
4. x = −4
5. y = −4x − 5
6. y = − 7
7. 4x − y = 2
8. y = 5 −

Hint:

Slopes that are opposite reciprocals of each other are perpendicular, while parallel lines share the same slope.

Hint (a):

Slope is given in the equation.

Hint (b):

y = 3 is a horizontal line, thus its slope is zero.

Hint (c):

Rearrange the equation into the y = mx + b form to identify the slope.

Hint (d):

x = −4 is a vertical line, thus its slope is undefined.

Hint (e):

Slope is given.

Hint (f):

Slope is given.

Hint (g):

Rearrange the equation into the y = mx + b form to identify the slope.

Hint (h):

Rearrange slightly and identify the slope.

Answer:

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?