Question 54549
resolution:
 p = peanuts and c = cashews
p + c = 20
2p + 5c = 2.75(20)

multiple top linear equation by (-2) and sum

-2p -2c = -40
2p + 5c = 55
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     3c = 15
     3c/3 = 15/3
      c = 5
p + 5 = 20
p = 20 -5
p = 15

you need 15 pound of peanuts and 5 pounds of cashews