Word Problems
Create and solve a system of equations to
answer each word problem
Kristen spent $131 on
shirts. Fancy shirts cost
$28 and plain shirts cost
$15. If Kristin bought a
total of 7 shirts, how many
of each kind did she buy?
#1
Let x = # of plain shirts
(-15) x + y = 7
15x +28y = 131
- 15x - 15y = -105
Let y = # of "fancy" shirts
x +2 = 7
-2 -2
x =5
15x +28y = 131
13y 26
=
13 13
y =2
Final Answer : 5 plain shirts and 2 fancy shirts
A piggy bank holds $3.35
worth of nickels and
quarters. If there is a total
of 19 coins in the piggy
bank, find the number of
nickels and the number of
quarters in the piggy bank.
#2
Let x = # of nickels
(-5)
x + y = 19
5x +25y = 335
- 5x - 5y = -95
Let y = # of quarters
x + 12 = 19
- 12 - 12
x=7
5x +25y = 335
20y 240
=
20
20
y = 12
Final Answer : 7 nickels and 12 quarters
The debate club sells pizza after
school as a fundraiser. Plain
slices cost $1.50 while Meatball
slices cost $2.50. The club sold
a total of 82 slices of pizza and
made a total of $173. How
many plain slices and how
many meatball slices did they
sell?
#3
Let x = # of plain slices Let y = # of meatball slices
(-1.5)
x + y = 82
x + 50 = 82
1.5x +2.5y = 173
- 50
- 1.5x - 1.5y = -123
x = 32
- 50
1.5x +2.5y = 173
y = 50
Final Answer : 32 plain slices and 50 meatball slices
There are 13 animals in a
barn. Some are chickens
and some are pigs. The
animals have a combined
total of 40 legs. How many
of each animal is there?
#4
Let x = # of chickens
(-2)
x + y = 13
2x + 4y = 40
-2x -2y = -26
Let y = # of pigs
x + 7 = 13
-7
x =6
2x + 4y = 40
2y 14
=
2 2
y =7
Final Answer : 6 chickens and 7 pigs
-7
I am thinking of two numbers:
The first number plus three
times the second number
equals 36. The second number
is five more than two times the
first number.
Find both numbers.
#5
Let x = the first number
Let y = the second number
x + 3y = 36
y = 2 (3) + 5
y = 2x + 5
y =6+5
x + 3(2x + 5 ) = 36
y = 11
x + 6x + 15 = 36
7x + 15 = 36
- 15
-15
7x 21
=
7 7
x =3
Final Answer : The first number is 3 and the second number is 11