7th grade Unit 2 Study Guide

The price of a dozen eggs was $1.63. Suppose the price increases m dollars per dozen and then the price decreases $0.12 per dozen, as reflected by the expression 1.63+m−0.12.

Which expression more concisely represents the current price of eggs after the two price changes?

• 1.51m

• m+1.51

• m-1.51

• m+1.75

• 1.51-m

Use the distributive property to expand the linear expression.

3(4x + 3)

• 12x + 9

• 12x + 6

Jasmine is on a cell phone plan where she pays $20 a month plus $0.10 per text message. She does not want to spend more than $40 on her cell phone bill. Write and solve the inequality that will tell her how many text messages she can send.

• 20 + 10x ≤ 40;

  She can send 2 text messages.

• 20 + 10x ≥ 40;

  She can send 2 text messages.

• 20 + 0.10x ≤ 40;

  She can send 20 text messages

• 20 + 0.10x ≤ 40;

  She can send 200 text messages.

The Mitchell family is renting a boat for the day. The boat rental has a flat fee of $100 plus $20 for each hour. They have to pay for a whole hour even if they are not out on the lake for a whole hour. For example, if they rent the boat for 3 and one-half hours, they have to pay for 4 hours.

If they want to spend $250 or less on the boat rental for the day, how many hours can they rent the boat? Formulate an inequality and solve.

• 
  100 + 20x ≤ 250; They can boat for 7 hours.

• 100 + 20x ≥ 250; They can boat for 8 hours.

• 100 + 20x ≤ 250; They can boat for 8 hours.

• 100 + 20x ≥ 250; They can boat for 7 hours.

Simplify: -0.8b + 4.1c - (-3.2b) - 0.1c

• 
  -2.4b + 4c

• 2.4b + 4c

• 2.4c + 4b

• 2.4b - 4c

• x = 24

• x = 18

• x = -18

• x = -24

What is the solution set for 16.5 ≥ 1.25x + 12.75?

• x ≤ -3

• x ≥ -3

• 
  x ≥ 3

• x ≤ 3

Expand the expressions and simplify.

5(x + 4) + 3(x + 2) =

• 6x + 18

• 8x + 4

• 8x + 26

• 7x - 18

4(x + 3) + 2(x − 4) =

• 6x + 4

• 8x + 26

• 6x - 18

• 6x + 18

4(x + 2) + 2(x + 5) =

• 8x + 4

• 6x + 18

• 7x - 18

• 8x + 26