At the shopping mall, Joaquin bought 4 pretzels and a bottle of water for $11.50. Kelly bought 3 pretzels and a bottle of water for $9.00. What is the price of a bottle of water?

2 Answers
Aug 4, 2016

Water: #color(green)($1.50)#

Explanation:

Let #P# be the price of a pretzel
and #W# be the price of a bottle of water.

We are told
[1]#color(white)("XXX")4P + 1W = 11.50#
[2]#color(white)("XXX")3P + 1W =9.00#

Subtracting [2] from [1] we get
[3]#color(white)("XXX")1P =2.50#

Substituting #2.50# for #P# in [1], we get
[4]#color(white)("XXX")4xx2.50+1W=11.50#
or
[5]#color(white)("XXX")1W=1.50#

Aug 4, 2016

The price of a bottle of water is 5.50$

Explanation:

The price of one pretzel is x$.

The price of one water bottle is y$.

4x+y=11.50
3x+y=9.00

subtract the second equation from first

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The price of a bottle of water is 5.50$