Unit 4 Test Review- Writing Linear Equations

Unit 4 Test Review- Writing Linear Equations

You can complete the review as many times as you like for a higher score.

Multiple Choice

What does 'b" represent in y=mx+b

• y-intercept

• x-intercept

• nothing

• slope

Multiple Choice

In the equation y=mx+b, what does the m represent?

• slope
• y-intercept
• linear
• point-slope

Multiple Choice

How would you write the equation with a slope of 2/3 and a y-intercept of (0, -3)

• y=3/2x+3
• y=2/3-3
• y=2/3x-3
• y=2/3x+3

Slope(m) from a Graph

• Pick two points on the graph

• Down is negative/ Up is positive

• Run is always right

• m = -1/3

Equation from Graph

• Count slope m = rise/run

• Find b, the y-intercept

• Plug in m and b into y = mx +b

So the equation would be
y = -1/3 x + 5

Multiple Choice

Write the equation of the graph by counting the slope and finding the y-intercept.

• y = 6/5x + 2

• y = -6/5x + 2

• y = 5/6x + 2

• y = -5/6x + 2

Multiple Choice

Write the equation of the line counting the slope and finding the y-intercept.

• y= -1x-3
• y= -3x-1
• y=-1/3x-1
• y= -3x-3

Multiple Choice

What is the equation of a horizontal line that goes through the point

(6, 7) ?

• x = 6

• x = 7

• y = 6

• y = 7

Multiple Choice

What is the equation of a vertical line that goes through point

(-3,5)?

• x = -3

• x = 5

• y = -3

• y = 5

Multiple Choice

Write the equation in point-slope form of the line that passes through the given point and has the given slope:

(-2, -1); m= -3

Don't forget to turn the double negatives into positives.

SHOW WORK ON PAPER

• y + 1 = -3(x - 2)

• y + 1 = -3(x + 2)

• y - 1 = 3(x - 1)

• y + 2 = -3(x + 1)

Multiple Choice

Write the equation in point-slope form of the line that passes through the given point and has the given slope.

(4, -7); m = -1/4

SHOW WORK ON PAPER

• y + 7 = -1/4(x - 4)

• y - 4 = -1/4(x + 7)

• y + 7 = 4(x - 4)

• y - 7 = -1/4(x - 4)

Equation of Lines

To find the equation of a line in slope-intercept form you must use point-slope form.

Find the equation of a line given two points.

If they give you two points you must first find the slope









then continue like we did the previous problems use point-slope form.

Multiple Choice

Find the equation of the line that passes through the points:

(-4, -2) and (-3, 5)

SHOW WORK ON PAPER

• y = ¹/₇ x + 26

• y = 7x + 26

• y = -7x + 26

• y = -7x - 26

Multiple Choice

Find the equation of the line that passes through the points:

(2, 2) and (3, 4)

SHOW WORK ON PAPER

• y = 2x + 2

• y = -2x - 2

• y = -2x + 2

• y = 2x - 2

Multiple Choice

What is the slope of a line perpendicular to 5?

Opposite Reciprocal!

• 5

• 1/5

• -1/5

• -5

Multiple Select

Which two lines are parallel because they have the SAME SLOPE(m)?

• $$y=3x+5$$

• $$y=-3x-2$$

• $$y=-\frac{1}{3}x+4$$

• $$y=3x-7$$

Multiple Select

Which two lines are perpendicular because they have the OPPOSITE RECIPROCAL SLOPE(m)?

• $$y=3x+5$$

• $$y=-\frac{1}{3}x+4$$

• $$y=\frac{1}{3}x+9$$  

Multiple Choice

Write the point-slope form through (3,4), parallel to  $$y=\frac{9}{2}x-5$$  

• $$y-3=\frac{9}{2}\left(x-4\right)$$  

• $$y+3=\frac{9}{2}\left(x+4\right)$$  

• $$y+4=\frac{9}{2}\left(x+3\right)$$  

• $$y-4=\frac{9}{2}\left(x-3\right)$$  

Multiple Choice

Write the equation of the line through (5,2) perpendicular to $$y=−5x−3$$  
  

• $$y-5=\frac{1}{5}(x-2)$$  

• $$y-5=5(x-2)$$  

• $$y-2=5\left(x-5\right)$$  

• $$y-2=\frac{1}{5}\left(x-5\right)$$  

Word Problems

Slope-Intercept Form: y=mx + b

• m is the slope or rate of change

• b is the y-intercept, which is our starting point

• Rates/slope can be described with phrases "each, for each, per..."

• Starting points sometimes use phrases like "initial, flat rate, one-time fee, ..."

Multiple Choice

Jim paid a gym membership fee of $50, plus $20 per month. Which equation would be used to model the total charge?

• c = 20m +50

• c = 50m + 20

• c = 50 + 20

• c = 20m

Multiple Choice

$$c=20m\ +50$$  is used to model Jim's total charge for his gym membership, where c is the total charge and m is the number of months.

How much would Jim be charged for 3 months?

• $150

• $20

• $60

• $110

Multiple Choice

Ja'Kaia saved $500 from her birthday and Christmas. She is spending about $25 per week.

• y = 500x + 25

• y = -500x + 25

• y = 25x + 500

• y = -25x + 500

Multiple Choice

Basmala is saving money to buy new iphone. She has saved $50 so far and plans to $20 each week for the next few months. Write an equation that represents how much money she will have after x weeks.

• y = 50x + 20

• y = -50x + 20

• y = 20x + 50

• y = -20x + 50

Multiple Choice

The initial fee to have a website set up is $60. It costs $44 per month to maintain the website. Write a function that represents the total cost of setting up and maintaining a website for x months.

• y = 44x + 60

• y = 60X + 44