document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=205608>Question 205608</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0395461405/algebrahomeworkh>Algebra</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> An experienced plumber maide $600 for working on a certain job. his apprentice, who makes $3 per hour less, also made 600. However, the apprentice worked 10h more than the plumber. How much does the plumber make per hour? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #155238 by </B><A HREF=/tutors/aboutme.mpl?userid=ptaylor><B>ptaylor(2198)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ptaylor><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/cgi-bin/show-face.mpl?user=ptaylor><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=155238\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let x=hourly wages of the plumber<BR>\n" );
document.write( "Then x-3=hourly wages of his apprentice<BR>\n" );
document.write( "Let y=number of hours the plumber worked<BR>\n" );
document.write( "Then y+10 =number of hours the apprentice worked\r<BR>\n" );
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document.write( "Now we know that the amount made by the plumber=x*y=$600----eq1<BR>\n" );
document.write( "We also know that amount made by the apprentice=(x-3)(y+10)=$600----eq2\r<BR>\n" );
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document.write( "So, our equation to solve is:<BR>\n" );
document.write( "xy=(x-3)(y+10) expand right side using FOIL (First, Outer, Inner, Last)<BR>\n" );
document.write( "xy=xy+10x-3y-30  subtract xy from each side; also add 3y and 30 to each side<BR>\n" );
document.write( "xy-xy+3y+30=xy-xy+10x-3y+3y-30+30  collect like terms<BR>\n" );
document.write( "3y+30=10x substitute y=600/x from eq1 <BR>\n" );
document.write( "3(600/x)+30=10x  multiply each term by x<BR>\n" );
document.write( "1800+30x=10x^2  divide each term by 10<BR>\n" );
document.write( "x^2-3x-180=0  quadratic in standard form and it can be factored<BR>\n" );
document.write( "(x-15)(x+12)=0<BR>\n" );
document.write( "x=-12-------------------no good!  wages are positive<BR>\n" );
document.write( "and<BR>\n" );
document.write( "x=$15---------------------plumber's hourly wages<BR>\n" );
document.write( "x-3=15-3=$12------------apprencice's hourly wages<BR>\n" );
document.write( "substitute x=15 into eq1<BR>\n" );
document.write( "15y=600<BR>\n" );
document.write( "y=40  hours worked by plumber<BR>\n" );
document.write( "y+10=40+10=50--------------hours worked by apprentice\r<BR>\n" );
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document.write( "CK<BR>\n" );
document.write( "50*12=40*15=600<BR>\n" );
document.write( "600=600=600<BR>\n" );
document.write( "Hope this helps---ptaylor </SPAN>\n" );
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