Geometry - (LT 8) Writing Equations of Lines

Geometry - Writing Equations of Lines

#1 on your paper:  Write the equation of the line from the graph.

• Slope  $m\ =\ -\frac{1}{2}$   

• y-intercept; b = 2

•  $Equation;\ \ \ \ y=-\frac{1}{2}x+2$  
  

Multiple Choice

#2 on your paper: Write the equation of the line given the graph.

• y = 1/2x - 4

• y = -4x + 2

• y = 2x - 4

Multiple Choice

#3 on your paper: Write the equation of the line given the graph.

• $y=-1x+3$
  

• $y=-\frac{4}{5}x+3$

• $y=3x+4$
  

Parallel and Perpendicular Lines

• Parallel - SAME SLOPE and DIFFERENT Y-INTERCEPT

• Perpendicular - Opposite Reciprocal

Parallel Slopes

• y = 2x - 1 and y = 2x + 5

• y = -7x + 6 and y = -7x - 5

Multiple Choice

Which lines are considered Parallel?

•  $y=2x-6$  

  
   $y=-2x+6$  
  

•  $y=\frac{1}{2}x+4$  

  
   $y=-2x-2$  
  

•  $y=-6x+5$  

  
   $y=-6x-10$  
  

Perpendicular Slopes

• What do you notice about the pair of pink numbers?

• What do you notice about the pair of green numbers?

Multiple Choice

Which lines are considered Perpendicular?

•  $y=2x-6$ 
   $y=-2x+6$  
  

•  $y=\frac{1}{2}x+4$  

  
   $y=-2x-2$  
  

•  $y=-6x+5$  

  
   $y=-6x-10$  
  

Multiple Select

Which lines are considered Neither parallel nor perpendicular? (Select all that apply)

•  $\ y=-2x+6$  
  
   $y=2x-6$  

•  $y=\frac{1}{2}x+4$  
  
   $y=2x-2$  

•  $y=-6x+5$  

  
   $y=\frac{1}{6}x-10$  
  

Multiple Choice

#4 on your paper:

Write the equation of the line in slope-intercept form that contains the points (-3,7) and (6,-5). What is the first step?

Multiple Choice

#4 on your paper:  

Write the equation of the line in slope-intercept form that contains the points (-3,7) and (6,-5). What did you get for the slope?

•  $m=-\frac{3}{4}$ 

• $m=-1$

•  $m=-\frac{4}{3}$ 

Multiple Choice

#4 on your paper:

Write the equation of the line in slope-intercept form that contains the points (-3,7) and (6,-5). What does the second step look like?

•  $y+7=-\frac{4}{3}\left(x-3\right)$ 

•  $y-7=-\frac{4}{3}\left(x--3\right)$ 

•  $y-7=\frac{4}{3}\left(x-3\right)$ 

Multiple Choice

#4 on your paper:

Write the equation of the line in slope-intercept form that contains the points (-3,7) and (6,-5). What is the equation for the line?

•  $y=-\frac{4}{3}x+3$ 

•  $y=-\frac{4}{3}x+11$ 

•  $y=-\frac{4}{3}-11$ 

Multiple Choice

#5 on your paper:

Write the equation of the line in slope-intercept form that contains the point (-1,4) and is parallel to the line: y = -5x - 8. (What is the first step?)

Multiple Choice

#5 on your paper:

Write the equation of the line in slope-intercept form that contains the point (-1,4) and is parallel to the line: y = -5x - 8.  (What is the final equation?)

• $y=-5x-1$

• $y=-5x+9$

•  $y=-5x+4$