Define Variables Word Problems

Gabby and Sydney bought some pens and pencils. Gabby bought 4 pens and 5 pencils for $6.71. Sydney bought 5 pens and 3 pencils for $7.12. Find the cost of each.

Select the two choices below that define your variables.

• x = the cost of a pen

• y = the cost of a pencil

• x = 9 pens

• y = 8 pencils

Gabby and Sydney bought some pens and pencils. Gabby bought 4 pens and 5 pencils for $6.71. Sydney bought 5 pens and 3 pencils for $7.12. Find the cost of each.

• The cost of a pen is $1.19 and the cost of a pencil is $0.39.

• The cost of a pencil is $1.19 and the cost of a pen is $0.39.

• The cost of a pen is $6.71 and the cost of a pencil is $7.12.

• The cost of a pen is $7.12 and the cost of a pencil is $6.71.

Mary has a collection of nickels and quarters for a total value of $4.90. If she has 42 coins total, how many of each kind are there? Select the two choices below that define your variables.

• x = number of quarters

• y = number of nickels

• x = 42 coins

• y = $4.90

Mary has a collection of nickels and quarters for a total value of $4.90. If she has 42 coins total, how many of each kind are there?

• Mary has 28 nickels and 14 quarters.

• Mary has 14 nickels and 28 quarters.

• Mary has $4.90.

• Mary has 42 coins.

Define the variables for this systems word problem. (Defina las variables para este problema de palabras del sistema.)

• x - # of multiple choice questions & y - # of word problems//x - # de preguntas de elección múltiple e y - # de problemas de palabras

• x - 1 point and y - 5 points//x - 1 puntos e y - 5 puntos

• x - 40 questions & y - 100 points//x - 40 preguntas e y - 100 puntos

The talent show committee sold a total of 530 tickets in advance. Student tickets cost $3 each and the adult tickets cost $4 each. If the total receipts were $1740, which system could be used to find how many of each type of ticket were sold? (Define your variables!)

• S + A = 530
  3S + 4A = 1740

• S + A = 530
  4S + 3A = 1740

• S + A = 1740
  3S + 4A = 530

• S + A = 1740
  4S + 3A = 530

At a college bookstore, Carla purchased a math textbook and a novel that cost a total of $54, not including tax. If the price of the math textbook, t, is $8 more than 3 times the price of the novel, n, which system of linear equations could be used to determine the price of each book?

• t + n = 54
  t = 3n + 8

• t + n = 54
  n = 3t + 8

• t + n = 54
  t = 3n - 8

• t + n = 8
  t = 3n + 54

A variable represents what is ______________. 

• the answer

• the operation

• the difference

• unknown 

What are the variables in the following expression?

• 3, 4, 1 and 7

• z, x and y

• + and -

• 15

Write the following statement as a mathematic expression with variable(s):

> The difference of 16 and K is seven.