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Dany bought a total of 20 game cards some of which cost $0.25 each and some of which cost $0.15 each. If dany spent $4.20to buy these cards,how many cards of each type did he buy?

Respuesta :

carlosego

For this case we have to:

x: Represents the $ 0.25 game cards

y: Represents the $ 0.15 game cards

We have then:

[tex]0.25x + 0.15y = 4.20\\x + y = 20[/tex]

From the second equation we have:

[tex]x = 20-y[/tex]

Substituting in the first equation:

[tex]0.25 (20-y) + 0.15y = 4.20\\5-0.25y + 0.15y = 4.20\\5-0.1y = 4.20\\-0.1y = 4.20-5\\-0.1y = -0.8\\y = \frac {0.8} {0.1}\\y = 8[/tex]

So, I buy 8 game cards for $ 0.15

On the other hand we have:

[tex]x = 20-8\\x = 12[/tex]

So, I buy 12 game cards for $0.25

Answer:

Buy 8 game cards for $0.15

Buy 12 game cards for $0.25

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