Question 982216
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Q1:
W=walnuts; P=pecans
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W+P=10 lbs
W=10 lbs-P Use this to substitute for W.
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$2.80W+$3.20P=$30.60 Substitute for W from above.
$2.80(10lbs-p)+$3.20P=$30.60 
$28.00-$2.80P+$3.20P=$30.60 
$0.40P=$2.60
P=6.5 lbs ANSWER 1: She bought 6.5 ponds of pecans.
W=10lbs-P=10 lbs-6.5 lbs=3.5 lbs
ANSWER 2: She bought 3.5 pounds of walnuts.
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CHECK:
$2.80W+$3.20P=$30.60
$2.80(3.5)+$3.20(6.5)=$30.60
$9.80+$20.80=$30.60
$30.60=$30.60
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