document.write( "Question 551946: mr.magoo's piggy bank contains 46 dimes and quarters. The value of his coins is $6.70. how many of each type of coin does he have? \n" ); document.write( "
Algebra.Com's Answer #359998 by TutorDelphia(193)\"\" \"About 
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So we know two basic facts:
\n" ); document.write( "d+q=46 (the number of dimes plus the number of quarters in 46)
\n" ); document.write( "And the values add up to 6.70
\n" ); document.write( "d*.10+q*.25=6.70
\n" ); document.write( "Now its easy to see this is a systems of equations problem. You can solve it with substitution or elimination.
\n" ); document.write( "I'll use elimination.
\n" ); document.write( "d+q=46
\n" ); document.write( "d*.10+q*.25=6.70 (divide both sides by .1 (which happens to be the same as multiplying by 10))
\n" ); document.write( "d+q*2.5=67
\n" ); document.write( "d+q=46 subtract this equation from the other one
\n" ); document.write( "q*1.5=21
\n" ); document.write( "q=14
\n" ); document.write( "sub in for q
\n" ); document.write( "d+14=46
\n" ); document.write( "d=32\r
\n" ); document.write( "\n" ); document.write( "If you did it by substitution you'd have to solve the equation:
\n" ); document.write( "(46-q)*.10+q*.25=6.70\r
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