document.write( "Question 911557: Joaquin buys 3 packs of light bulbs.each pack contains 12 light bulbs.after changing the bulbs in his house,he has 15 bulbs left.How many light bulbs did he use? \n" ); document.write( "
Algebra.Com's Answer #553286 by KMST(5328)\"\" \"About 
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In 3 packs of light bulbs, with each pack containing 12 light bulbs, Joaquín had
\n" ); document.write( "\"3%2A12=36\" light bulbs.
\n" ); document.write( "If Joaquín used as many bulbs as he needed to change all the bulbs in his house, and he has 15 bulbs left,
\n" ); document.write( "then he used \"36-15=highlight%2821%29\" bulbs.
\n" ); document.write( "If an equation was needed, we could say
\n" ); document.write( "\"x\"= number of bulbs Joaquín used. So,
\n" ); document.write( "\"15=36-x\" ---> \"15%2Bx=36\" ---> \"x=36-15\" ---> \"highlight%28x=21%29\" .
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