SOLUTION: Star Cups, a specialty coffee store, creates a special mix of two coffees at two different prices: $6.42 and $7.28 per pound each. How many pounds of the $7.28 coffee should be mix

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Question 1152018: Star Cups, a specialty coffee store, creates a special mix of two coffees at two different prices: $6.42 and $7.28 per pound each. How many pounds of the $7.28 coffee should be mixed with 7 pounds of $6.42 coffee to sell the mixture for $7.20 per pound?
I have the answer of 68.25 lbs but am a bit confused at the solution process.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +x+ = pounds of $7.28 coffee needed
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+%28+6.42%2A7+%2B+7.28x+%29+%2F+%28+7+%2B+x+%29+=+7.2+
+%28+44.94+%2B+7.28x+%29+%2F+%28+7+%2B+x+%29+=+7.2+
+44.94+%2B+7.28x+=+7.2%2A%28+7+%2B+x+%29+
+44.94+%2B+7.28x+=+50.4+%2B+7.2x+
+.08x+=+5.46+
+x+=+68.25+
68.25 pounds of $7.28 coffee are needed
Hope this is clear
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check:
+%28+6.42%2A7+%2B+7.28x+%29+%2F+%28+7+%2B+x+%29+=+7.2+
+%28+6.42%2A7+%2B+7.28%2A68.25+%29+%2F+%28+7+%2B+68.25+%29+=+7.2+
+%28+44.94+%2B+496.86+%29+%2F+75.25+=+7.2+
+541.8+%2F+75.25+=+7.2+
+541.8+=+541.8+
OK