Grade 8 Benchmark 2 Review

​This is a review of the Benchmark. Please study the notes before attempting the problems. Read each problem carefully.

Linear Relationships

​How to determine the slope and y-intercept from a word problem.

• the slope will be followed by, 'per', 'for every', 'for each' or 'each'.

• the y-intercept is the initial or starting amount.

• Example: Jonah started a new job. He decides to save money. Before he started working he had $50. Jonah decides to save $20 each week.

• Since Jonah starts with $50, we can say the y-intercept, b, is 50. And since $20 is followed by, 'each'. the slope, m, is 20.

• We write the equation as y=20x + 50 or y= 50 + 20x

Multiple Choice

Jada is saving money. Jada start with $400 in her savings account and adds $15 per week. Identify the slope (m) and the y-intercept (b).

• m=400 and b=15

• b=400 and m=15

Multiple Choice

Christina is saving money. She starts with $250 in her savings account and adds $25 each week. Identify the slope (m).

• 250

• 275

• 25

• 225

Multiple Choice

A new music app charges 1.95 for a subscription and 0.75 for each song downloaded. What is the slope?

• 0.75

• 1.95

• 1.20

Multiple Choice

A new music app charges 1.95 for a subscription and 0.75 for each song downloaded. What is the y-intercept?

• 0.75

• 1.95

• 1.20

Multiple Choice

A car rental company charges $42 per day for a rented car and $0.75 for every mile driven. Which equation is written correctly.

• y=42x - 0.75

• y=42x + 0.75

• y=0.75x - 42

• y = 0.75x + 42

Multiple Choice

Challenge 1:

The value in dollars, y, of a laptop computer x months after it was purchased can be modeled by y= 550 - 25x. Identify the slope and describe its meaning.

• the slope is -25 which means the value went down $25 each month

• the slope is 550 which means the value went up $550 each month

• the slope is 25 which means the value went up $25 each month

• the slope is -550 which means the slope went down $550 each month

Multiple Choice

Challenge 2:

Jada and Christina are saving money. Jada starts with $400 and adds $15 per week. Christina starts with $250 and adds $25 each week. Who will have more money in the account after 13 weeks?

hint: you must write an equation for each and determine how much money each girl will have afer 13 weeks when x= the number of weeks.

• Jada

• Christina

• They will have the ame amount