Expressions and Number Problems

Which expression matches: twice a number, decreased by four.

• 2x - 4

• x - 4

• (x ÷ 2) – 4

• 2x + 4

There are r rows of chairs with 7 chairs in each row. Choose the expression that shows the number of chairs in total.

• 7r

• 7/r

• r-7

• r+7

Kenneth has g gumballs. Maggie has 29 fewer gumballs than Kenneth. Choose the expression that shows how many gumballs Maggie has.

• g+29

• g-29

• 29g

• g ÷ 29

Five times Connor's age increased by 9

• 5(x+9)

• 9(5+x)

• 9x+5

• 5x+9

Simplify:

• -4x - 3

• x² - 3

• -4x² - 6x

• -4x - 6

Mrs. Guang purchased four airline tickets to Florida. She will also pay a fee of $55 for an extra piece of luggage. Define a variable and write an expression to represent her total cost of flying to Florida.

• l = (pieces of) luggage

• 4l + 55

• 55t + 4

• t = (number of) tickets

• 4t + 55

• 55l + 4

A camp leader figures that she needs one tent for every three campers, plus a tent for herself. Define a variable and write an expression to represent the number of tents needed.

​ ​ (a)   ​ ​ ​ ​ (b)  

• 1c + 3

• 3c + 1

• t = tents

• 1t + 3

• 3t + 1

• c = (number of) campers

Choose the algebraic expression that matches the verbal phrase.

• A) x + y

• B) x - y

• C) x * y

• D) x / y

A plumber charges $50 to visit a house plus $40 for every hour of work. Define a variable and write an expression to represent the total cost of hiring a plumber.

​ (a)   ​ (b)  

• h = hours (of work)

• 40h + 50

• 50v + 40

• 50h + 40

• 40v + 50

• v = visits

Write an expression to represent the following situation.

Susan's age in three years, when a represents her present age.

Mathematical Equivalence

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