document.write( "Question 224659: Jake has 205 coins consisting of nickels, dimes, and quarters. If the total value of the coins is $22 and there are three times as many dimes as nickels, how many of each coin did he have? \n" ); document.write( "
Algebra.Com's Answer #167850 by drj(1380)\"\" \"About 
You can put this solution on YOUR website!
Jake has 205 coins consisting of nickels, dimes, and quarters. If the total value of the coins is $22 and there are three times as many dimes as nickels, how many of each coin did he have?\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Step 1. Let x be the number of nickels.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Step 2. Let 0.05x be the dollar value of nickels.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Step 3. Let y be the number of dimes\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Step 4. Let 0.10y be the dollar value of dimes.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Step 5. Let z be the number of quarters.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Step 6. Let 0.25z be the dollar value of quarters.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Step 7. Then x+y+z=205 since the total number of coins is 205.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Step 8. Then 0.05x+0.10y+0.25z=22 since the dollar value of nickels, dimes, and quarters is 22.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Step 9. We are also given y=3x since there are three times as many dimes as nickels.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Step 10. Here's our system of linear equations given in Steps 7, 8, and 9.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x%2By%2Bz=205\" Equation A
\n" ); document.write( "\"0.05x%2B0.10y%2B0.25z=22\" Equation B
\n" ); document.write( "\"y=3x\" Equation C\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Substitute Equation C into Equations A and B\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x%2B3x%2Bz=205\" or \"4x%2Bz=205\" Equation A1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"0.05x%2B0.10%283x%29%2B0.25z=22\" or \"0.35x%2B.25z=22\" Equation B1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: SOLVE linear system by SUBSTITUTION
Solve:
\n" ); document.write( " We'll use substitution. After moving 1*z to the right, we get:
\n" ); document.write( " \"4%2Ax+=+205+-+1%2Az\", or \"x+=+205%2F4+-+1%2Az%2F4\". Substitute that
\n" ); document.write( " into another equation:
\n" ); document.write( " \"0.35%2A%28205%2F4+-+1%2Az%2F4%29+%2B+0.25%5Cz+=+22\" and simplify: So, we know that z=25. Since \"x+=+205%2F4+-+1%2Az%2F4\", x=45.
\n" ); document.write( "
\n" ); document.write( " Answer: \"system%28+x=45%2C+z=25+%29\".
\n" ); document.write( "

\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "With \"x=45\" and \"z=25\" then \"y=205-45-25=135\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Check dollar value...\"45%2A0.05%2B135%2A0.10%2B25%2A0.25=+2.25%2B13.50%2B6.25=22\"...which is a true statement.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Step 11. ANSWER: The number of nickels is 45, the number of dimes is 135, and the number of quarters is 25.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "I hope the above steps were helpful.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Good luck in your studies!\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Respectfully,
\n" ); document.write( "Dr J\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );