Equations of Parallel and Perpendicular Lines

If two lines are parallel their slopes are  ____________

• the same.
• negative reciprocals of each other.

Are these lines parallel?
y = 12x + 4
y = 12x +14

• YES
• NO

Are these lines parallel?

y = (-1/2)x + 1

y = (1/2)x - 5

• YES

• NO

Write an equation of a line that passes through the point (5,-1) and is parallel to the line y = (-3/5)x -3

• y = (-3/5)x + 2
• y = (-3/5)x -2
• y = (3/5)x + 2
• y = (5/3) + 2

Write an equation of a line that passes through the point (2,6) and is parallel to the line y = -3

• y = 12
• y = 6
• x = 12
• x = 6

Are these lines perpendicular?
y = 4x + 2
y = (-1/4)x + 12

• YES
• NO

Write an equation of a line that passes through the point (-9,2) and is perpendicular to the line y = 3x - 12

• y = (-1/3)x - 1
• y = (1/3)x - 2
• y = -3x + 12
• y = 3x - 1

Slopes of parallel lines are...

• opposite reciprocals.

• opposites.

• identical.

• always 7.

Slopes of perpendicular lines are...

• opposite reciprocals.
• opposites.
• identical.
• always 7.

What slope is parallel to:  
m = 4

• 4
• -1/4
• -4
• 1/4