Writing Equations for Parallel and Perpendicular Lines

The video tutorial explains how to use the slopes of parallel and perpendicular lines to write equations of lines. It provides examples of finding the equation of a line perpendicular to y = 2x + 4 that passes through a specific point, and a line parallel to 3x + 2y = 1. The tutorial covers the concepts of opposite reciprocal slopes for perpendicular lines and maintaining the same slope for parallel lines. It also demonstrates how to convert equations to slope-intercept form and solve for the y-intercept.

What do we need to write the equation of a line?

• Slope and y-intercept

• The length of the line

• Slope and x-intercept

• Two points on the line

What is the slope of a line perpendicular to y = 2x + 4?

• 1/2

• -1/2

• -2

• 2

Tags

CCSS.8.EE.B.6

If a line passes through the point (-3, 4) and is perpendicular to y = 2x + 4, what is its y-intercept?

• 2.5

• -4

• 4

• -2.5

What does the graph of a line perpendicular to y = 2x + 4 look like?

• It goes downhill from left to right

• It is vertical

• It goes uphill from left to right

• It is horizontal

What is the first step in finding the equation of a line parallel to 3x + 2y = 1?

• Find the x-intercept

• Convert the equation to slope-intercept form

• Graph the line

• Find the y-intercept

What is the slope of the line parallel to 3x + 2y = 1?

• 2/3

• -3/2

• 3

• -2

Tags

CCSS.8.EE.B.5

If a line passes through the point (1, 5) and is parallel to 3x + 2y = 1, what is its y-intercept?

• -6.5

• 6.5

• 5

• 1

What does the graph of a line parallel to 3x + 2y = 1 look like?

• It intersects the original line

• It is identical to the original line

• It is perpendicular to the original line

• It never intersects the original line

What is the slope of a line that is the opposite reciprocal of -3/2?

• 3/2

• -2/3

• -3/2

• 2/3

Tags

CCSS.8.EE.B.5

What is the y-intercept of the line y = -3/2x + 6.5?

• 6.5

• -6.5

• -3

• 3

Tags

CCSS.8.EE.B.6

CCSS.8.F.A.3