document.write( "Question 1147868: Suppose you have just enough money, in coins, to pay for a loaf of bread priced at $1.95. You have 12 coins, all quarters and dimes. Let q equal the number of quarters and d equal the number of dimes. How many of each coin do you have? \r
\n" ); document.write( "\n" ); document.write( "I have the answer as 5 quarters and 7 dimes. I got it just by using common sense and did it in my head. Though, I would like to know how to actually solve it. All i’m really looking for is for the equation/s. From there on, I can figure out if it is substitution or elimination and solve it myself. \n" ); document.write( "

Algebra.Com's Answer #769197 by ikleyn(52799) $\"\"$ $\"About$

You can put this solution on YOUR website!
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document.write( "The equation system you are asking for is\r\n" );
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document.write( "    d +   q =  12      (1)   (counting coins)\r\n" );
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document.write( "  10d + 25q = 195      (2)   (counting money, in cents).\r\n" );
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document.write( "To solve the system, express d = 12-q  from equation (1) and substitute it into equation (2).  You will get\r\n" );
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document.write( "    10*(12-q) + 25q = 195\r\n" );
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document.write( "    120 - 10q + 25q = 195\r\n" );
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document.write( "    15q             = 195 - 120\r\n" );
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document.write( "    15q             = 75\r\n" );
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document.write( "      q             = 75/15 = 5.\r\n" );
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document.write( "ANSWER.  5 quarters and  12-5 = 7 dimes.\r\n" );
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\n" ); document.write( "\n" ); document.write( "For coin problems and their detailed solutions see the lessons in this site:\r
\n" ); document.write( "\n" ); document.write( "    - Coin problems\r
\n" ); document.write( "\n" ); document.write( "    - More Coin problems\r
\n" ); document.write( "\n" ); document.write( "    - Solving coin problems without using equations\r
\n" ); document.write( "\n" ); document.write( "    - Kevin and Randy Muise have a jar containing coins\r
\n" ); document.write( "\n" ); document.write( "    - Typical coin problems from the archive\r
\n" ); document.write( "\n" ); document.write( "    - Three methods for solving standard (typical) coin word problems\r
\n" ); document.write( "\n" ); document.write( "    - More complicated coin problems\r
\n" ); document.write( "\n" ); document.write( "    - Solving coin problems mentally by grouping without using equations\r
\n" ); document.write( "\n" ); document.write( "    - Non-typical coin problems \r
\n" ); document.write( "\n" ); document.write( "    - Santa Claus helps solving coin problem\r
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\n" ); document.write( "\n" ); document.write( "You will find there the lessons for all levels - from introductory to advanced,
\n" ); document.write( "and for all methods used - from one equation to two equations and even without equations. \r
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\n" ); document.write( "\n" ); document.write( "A convenient place to quickly observe these lessons from a \"bird flight height\" (a top view) is the last lesson in the list.\r
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\n" ); document.write( "\n" ); document.write( "Read them attentively and become an expert in this field.\r
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\n" ); document.write( "\n" ); document.write( "Also, you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lessons are the part of this online textbook under the topic \"Coin problems\".\r
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\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
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\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
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\n" ); document.write( "\n" ); document.write( "to your archive and use it when it is needed.\r
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