document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=170636>Question 170636</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0618044302/algebrahomeworkh>Algebra structure and method book one</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> Originally the dimensions of a rectangle were 20 cm by 23 cm. When both dimensions were decreased by the same amount, the area of the rectangle decreased by 120 cm^2. Find the dimensions of the new rectangle. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #125954 by </B><A HREF=/tutors/aboutme.mpl?userid=checkley77><B>checkley77(12844)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=checkley77><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=125954\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 20*23=460cm^2 is the original area.<BR>\n" );
document.write( "(20-x)(23-x)=460-120<BR>\n" );
document.write( "460-43x+x^2=340<BR>\n" );
document.write( "x^2-43x+460-340=0<BR>\n" );
document.write( "x^2-43x+120=0<BR>\n" );
document.write( "(x-40)(x-3)=0<BR>\n" );
document.write( "x-3=0<BR>\n" );
document.write( "x=3 <BR>\n" );
document.write( "Thus the new dimentions are:<BR>\n" );
document.write( "20-3=17<BR>\n" );
document.write( "23-3=20<BR>\n" );
document.write( "Proof:<BR>\n" );
document.write( "17*20=460-120<BR>\n" );
document.write( "340=340 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );