SOLUTION: at the nut shop 5 pounds of peanuts and 6 pounds of cashews cost $11.20. 3 pounds of peanuts and 7 pounds of cashews costs $10.80. What does the store charge for a pound of each?

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Question 1098769: at the nut shop 5 pounds of peanuts and 6 pounds of cashews cost $11.20. 3 pounds of peanuts and 7 pounds of cashews costs $10.80. What does the store charge for a pound of each?
Found 2 solutions by josmiceli, josgarithmetic:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = cost of 1 pound of peanuts in dollars
Let +b+ = cost of 1 pound of cashews in dollars
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(1) +5a+%2B+6b+=+11.2+
(2) +3a+%2B+7b+=+10.8+
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(1) +50a+%2B+60b+=+112+
(2) +30a+%2B+70b+=+108+
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(1) +25a+%2B+30b+=+56+
(2) +15a+%2B+35b+=+54+
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Multiply both sides of (1) by +15+
Multiply both sides of (2) by +25+
Subtract (1) from (2)
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You can finish this

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
p peanuts price
c cashews price

system%285p%2B6c=11.2%2C3p%2B7c=10.8%29----multiply first equation by 3, second equation by 5.

system%2815p%2B18c=33.6%2C15p%2B35c=54%29

15p%2B35c-%2815p%2B18c%29=54-33.6
17c=20.4
highlight%28c=1.2%29--------dollars per pound, cashews

p=%2811.2-6c%29%2F5
p=%2811.2-6%2A1.2%29%2F5
highlight%28p=0.8%29---------dollars per pound, peanuts