document.write( "Question 384578: Two mechanics worked on a car. The first mechanic worked for 20 hours, and the second mechanic worked for 5 hours. Together they charged a total of $2325 . What was the rate charged per hour by each mechanic if the sum of the two rates was $150 per hour? \n" ); document.write( "

Algebra.Com's Answer #272233 by stanbon(75887) $\"\"$ $\"About$

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Two mechanics worked on a car. The first mechanic worked for 20 hours, and the second mechanic worked for 5 hours. Together they charged a total of $2325 . What was the rate charged per hour by each mechanic if the sum of the two rates was $150 per hour?
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\n" ); document.write( "Let 1st mechanic rate be \"x dollars per hour\"
\n" ); document.write( "Let 2nd mechanic rate be \"y dollars per hour\"
\n" ); document.write( "---------------------------------------------------
\n" ); document.write( "Equations:
\n" ); document.write( "Value Eq: 20x + 5y = 2325
\n" ); document.write( "Rate Eq: x + y = 150 per hour
\n" ); document.write( "-----
\n" ); document.write( "Multiply thru the Rate equation by 20 to get:
\n" ); document.write( "20x + 20y = 20*150
\n" ); document.write( "-----
\n" ); document.write( "Subtract that from the value equation and solve for \"y\":
\n" ); document.write( "-15y = 2325 - 20*150
\n" ); document.write( "-15y = -675
\n" ); document.write( "y = $45
\n" ); document.write( "----
\n" ); document.write( "Substitute to solve for \"x\"
\n" ); document.write( "x + 45 = 150
\n" ); document.write( "x = $105
\n" ); document.write( "========================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "

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