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Pablo buys 4 sandwiches and 1 drink for $16. Susie buys 2 sandwiches and 2 drinks for $11. Find the price of each item.
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4s + d = 16, (1)
2s + 2d = 11. (2)
Multiply equation (1) by 2 (both sides). Then distract the equation (2) from it. You will get
8s - 2s = 32 - 11, or
6s = 21.
Hence, s =
.
Then d = 16 - 4s = 16 - 4*3.50 = 16 - 14 - 2.
Answer. The price for sandwich is $3.50, the price for drink is $2.