SOLUTION: A candy maker mixed marshmallows worth $1.80 a pound with rice crisipes worth $3.20 a pound to make 50 pounds of a rice crispie treats worth $2.92 a pound. Find the number of pound

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Question 1072588: A candy maker mixed marshmallows worth $1.80 a pound with rice crisipes worth $3.20 a pound to make 50 pounds of a rice crispie treats worth $2.92 a pound. Find the number of pounds of each item used.
I need help on this please help me :o

Found 2 solutions by stanbon, josmiceli:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A candy maker mixed marshmallows worth $1.80 a pound with rice crispies worth $3.20 a pound to make 50 pounds of a rice crispie treats worth $2.92 a pound. Find the number of pounds of each item used.
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weight:: m + r = 50 lbs
Value:::1.8m+3.2r = 2.92*50
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1.8m + 3.2(50-m) = 147.5
1.8m + 160 - 3.2m = 147.5
1.4m = 12.5
m = 8.93 lbs (amt. of marshmallows needed)
r = 41.07 lbs (amt. of rice crispies)
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Cheers,
Stan H.
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Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = pounds of MM used
Let +b+ = pounds of RC used
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(1) +a+%2B+b+=+50+
(2) +%28+1.8a+%2B+3.2b+%29+%2F+50+=+2.92+
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(2) +1.8a+%2B+3.2b+=+2.92%2A50+
(2) +1.8a+%2B+3.2b+=+146+
(2) +18a+%2B+32b+=+1460+
(2) +9a+%2B+16b+=+730+
Multiply both sides of (1) by +9+ and
subtract (1) from (2)
(2) +9a+%2B+16b+=+730+
(1) +-9a+-+9b+=+-450+
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+7b+=+280+
+b+=+40+
and
(1) +a+%2B+b+=+50+
(1) +a+%2B+40+=+50+
(1) +a+=+10+
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10 pounds of MM are needed
40 pounds of RC are needed
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check:
(2) +%28+1.8a+%2B+3.2b+%29+%2F+50+=+2.92+
(2) +%28+1.8%2A10+%2B+3.2%2A40+%29+%2F+50+=+2.92+
(2) +%28+18+%2B+128+%29+%2F+50+=+2.92+
(2) +146+=+2.92%2A50+
(2) +146+=+146+
OK