Answer:
Javon purchase Energy cards = 52
Javon purchase Dragon cards = 75
Step-by-step explanation:
Given - Javon spent $687 on pokemon cards. Energy cards cost $6
and dragon cards cost $5.
To find - If he bought a total of 127 packs then how many of each did he buy ?
Proof -
Let Javon purchase Energy cards = x
Javon purchase Dragon cards = y
Now,
Given that he bought a total of 127 packs
⇒x + y = 127
Also,
Cost for 1 Energy card = $6
⇒Cost of x Energy cards = $ 6x
And
Cost of 1 Dragon card = $5
⇒Cost of y Dragon card = $ 5y
Now,
Given that Javon spent $687 on pokemon cards.
⇒6x + 5y = 687
∴ we get
x + y = 127 ..................(1)
6x + 5y = 687 .................(2)
Multiply by 6 in equation (1) , we get
6(x + y) = 6(127)
⇒6x + 6y = 762 .................(3)
Now,
Subtract equation (2) from equation (1) , we get
6x + 6y - (6x + 5y )= 762 - 687
⇒6x + 6y - 6x - 5y = 75
⇒y = 75
Now,
Put the value of y in equation (1), we get
x + 75 = 127
⇒x = 127 - 75
⇒x = 52
∴ we get
Javon purchase Energy cards = x = 52
Javon purchase Dragon cards = y = 75
