4.3 & 4.4 Review

4.3 & 4.4 Review

By Lisa McClure-Wright

Solving an equation for y

Example

y+3x=7. -subtract 3x from both sides

y=-3x+7​ -slope intercept form y=mx+b

Some text here about the topic of discussion

Multiple Choice

Solve this equation for y

(Write your answer in slope intercept form)

$$y+2x=8$$  

• y=8-2x

• y= -2x+8

• y=2x+8

• y= -8+2x

Multiple Choice

Solve this equation for y

$$2y-6x=2$$  

(write your answer in slope intercept form)

• y= 1+3x

• y=6x+2

• 2y=6x+2

• y= 3x+1

Multiple Choice

Solve this equation for y

(write your answer in slope intercept form)

$$4x+y=7$$  

• y= -4x+7

• y= 7-4x

• y= 4x+7

• 4x= y+7

​Example

​Give the slope and y-intercept for the given equations. Rmember to write your y-intercept as a coordinate point.

Multiple Choice

Give the slope and y-intercept for the given equation.

$$y=2x+9$$  

• can not be determined

• m=9

  (0,2)

• m=2

  (0,9)

• m= -2

  (0,9)

Multiple Choice

What is the y-intercept of this equation?

$$2y+2x=2$$  

• (0,1)

• (0,2)

• (1,0)

• (2,0)

Example​

The cost y (in dollars) for x number of cans of soda is represented by the equation y=(1/2)x+1. Graph this situation.

• figure out the slope

  • y=mx+b

  • m is the slope; therefor the (1/2) is the slop​e

• figure out the y-intercept

  • y=mx+b

  • b is the y-intercept; therefor it is (0, 1)

• plot the y-intercept then use slope triangle to find another point

• Connect with a straight line

• Graph on the next slide​

​y=(1/2)x+1

Multiple Choice

The cost y (in dollars) for x number of shirts is represented by the equation

y=6x+1

Choose the graph that matches this equation

Multiple Choice

The cost y (in dollars) for x number of shirts is represented by the eqution

y=6x+1. Interpret the slope.

• 6 shirts cost $1

• Each shirt costs $1

• Each shirt cost $(1/6)

• Each shirt costs $6

Multiple Choice

The equation $$y=-2x+3$$  represents y, in gallons of water left in a barrel after x number of minutes. Which graph matches this situation.

Multiple Choice

The equation $$y=-2x+3$$  represents the amount y (in gallons) of water left in a barrel after draining for x number of minutes.

Which statement describes the slope for this situation?

• 2 gallons of water are drained every 3 mins

• 3 gallons of water are drained each min

• 2 gallons of water are added each min

• 2 gallons of water drain each min

​Example

Multiple Choice

Given the graph, write the equation that goes with this proportional relationship

• $$y=\frac{3}{2}x$$  

• $$y=\frac{2}{3}x$$  

• $$y=\frac{3}{2}x+3$$  

• $$y=\frac{2}{3}x+6$$  

Example

• ​y-intercept is (0, 2)

• plot that point then do a slope triangle ​

• The x-intercept is where it crosses the x-axis

  • x-intercept is (-2, 0)​

Multiple Choice

Graph the linear equation. Identify the the x-intercept.

$$y=-2x+4$$   

• x-intercept (-2, 0)

• x-intercept (4, 0)

• x-intercept (0,4)

• x-intercept (2,0)

Example

Multiple Select

Which of the following equations show a proportional relationship? There is more than one correct answer, click all that apply.

• $$y=9x$$  

• $$y=-2x+1$$  

• $$y=\frac{1}{2}x+\frac{1}{2}$$  

• $$y=-8x$$  

Example

​Given the graph, identify the x & y intercepts.

• Remember, the y-intercept is where the graph crosses the y-axis

• The x-intercept is where the graph crosses the x-axis​

• graph crosses the y-axis at 3 so the y-intercept is (0,3)

• graph crosses the x-axis at -15 so the x-intercept is (-15, 0)

Multiple Choice

Given the graph, identify the x & y intercepts

• y-int (0, 2)

  x-int (2, -2)

• y-int (0, 2)

  x-int (1, 0)

• y-int (1, 0)

  x-int (0, 2)

• can not be determined