Question

The school store is running a promotion on school supplies. Different supplies are placed on two shelves. You can purchese 3 items from shelf A and 2 items from shelf B for $16. Or you can purchase 2 items for shelf A and 3 from be for $14. How much more does one item on shelf A cost than an item on B? Show work and explain.

Answer 1

2 more dollars

Answer 2

3a + 2b = 16....multiply by 2
2a + 3b = 14...multiply by -3
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6a + 4b = 32 (result of multiplying by 2)
-6a - 9b = - 42 (result o multiplying by -3)
-----------------add
-5b = - 10
b = -10/-5
b = 2.....items on shelf B cost $ 2

3a + 2b = 16
3a + 2(2) = 16
3a + 4 = 16
3a = 16 - 4
3a = 12
a = 12/3
a = 4....items on shelf A cost $ 4

an item on shelf A costs (4 - 2) = 2 dollars more then an item on shelf B