document.write( "Question 1160512: Egg pencils cost $0.15 each and colored pencils cost $0.21 each if 24 pencils cost $4.02 how many of them were black \n" ); document.write( "
Algebra.Com's Answer #783810 by saw(34)\"\" \"About 
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b = black
\n" ); document.write( "c = colored
\n" ); document.write( "b+c = 24
\n" ); document.write( "0.15b+0.21c = 4.02
\n" ); document.write( "Use substitution
\n" ); document.write( "b = 24-c
\n" ); document.write( "0.15(24-c)+0.21c = 4.02
\n" ); document.write( "3.6-0.15c+0.21c = 4.02
\n" ); document.write( "3.6+0.06c = 4.02
\n" ); document.write( "0.06c = 4.02-3.6
\n" ); document.write( "0.06c = 0.42
\n" ); document.write( "Divide both sides by 0.06
\n" ); document.write( "c = 7
\n" ); document.write( "b = 24-7
\n" ); document.write( "b = 17
\n" ); document.write( "Check----
\n" ); document.write( "0.15b+0.21c = 4.02\r
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