document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=112096>Question 112096</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A bricklayer and an eectrician together 90 hours working on a new house. If the bricklayer earns $12 per hour, the electrician earns $16 per hour, and the wner pays them a total of $1350 for their work, how many hours does each worker spend on the house? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #81831 by </B><A HREF=/tutors/aboutme.mpl?userid=Earlsdon><B>Earlsdon(6294)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Earlsdon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=81831\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let x = the number of hours worked by the bricklayer and y = the number of hours worked by the electrician.<BR>\n" );
document.write( "The total number of hours worked together can be expressed by:<BR>\n" );
document.write( "x+y = 90<BR>\n" );
document.write( "The amount earned by the bricklayer can be expressed by:<BR>\n" );
document.write( "x($12)<BR>\n" );
document.write( "The amount earned by the electrician can be expressed by:<BR>\n" );
document.write( "y($16)<BR>\n" );
document.write( "So the total amount earned by both is:<BR>\n" );
document.write( "x($12)+y($16) = $1350\r<BR>\n" );
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document.write( "Now we have two equations with two unknowns:<BR>\n" );
document.write( "1) x+y = 90 Rewrite this as x = 90-y and substitute into equation 2) then solve for y.<BR>\n" );
document.write( "2) 12x+16y = 1350\r<BR>\n" );
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document.write( "2a) 12(90-y)+16y = 1350 Simplify.<BR>\n" );
document.write( "1080-12y+16y = 1350 Combine like-terms.<BR>\n" );
document.write( "1080+4y = 1350 Subtract 1080 from both sides.<BR>\n" );
document.write( "4y = 270 Divide both sides by 4.<BR>\n" );
document.write( "y = 67.5<BR>\n" );
document.write( "x = 90-y<BR>\n" );
document.write( "x = 90-67.5<BR>\n" );
document.write( "x = 22.5<BR>\n" );
document.write( "So the bricklayer worked 22.5 hours and the electrician worked 67.5 hours.\r<BR>\n" );
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document.write( "Check:<BR>\n" );
document.write( "x+y = 90<BR>\n" );
document.write( "22.5+67.5 = 90<BR>\n" );
document.write( "90 = 90\r<BR>\n" );
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document.write( "$12x+$16y = $1350<BR>\n" );
document.write( "$12(22.5)+$16(67.5) = $1350<BR>\n" );
document.write( "$270 + $1080 = $1350<BR>\n" );
document.write( "$1350 = $1350 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );