document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=391126>Question 391126</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a rectangle is 6 cm long and 4 cm wide. If each dimension is increased by the same number of centimeters, a new rectangle is formed whose area is 39 square centimeters more than the area of the original rectangle. By how may centimeters was each dimension increased? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #277621 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=277621\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let x =number of cm each side of the rectangle was increased<BR>\n" );
document.write( "area of rectangle = length * width<BR>\n" );
document.write( "length of new rectangle = (x+6)cm<BR>\n" );
document.write( "width of new rectangle = (x+4)cm<BR>\n" );
document.write( "given area of new triangle =39 cm^2\r<BR>\n" );
document.write( "\n" );
document.write( "(x+6)(x+4)=39<BR>\n" );
document.write( "x^2+10x+24=39<BR>\n" );
document.write( "x^2+10x-15=0<BR>\n" );
document.write( "use the following quadratic formula to solve for x<BR>\n" );
document.write( "with a =1,b=10,c=-15\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "x=((-10)ħsqrt(10^2-4*1*(-15))/2*1<BR>\n" );
document.write( "   = ((-10)ħsqrt(100+60)=-10ħsqrt(160))2<BR>\n" );
document.write( "    <BR>\n" );
document.write( "=(-10ħ12.65)/2=2.65/2 or -22.65/2<BR>\n" );
document.write( "=1.33 or -11.33(reject)\r<BR>\n" );
document.write( "\n" );
document.write( "ans: each side of the rectangle was increased by 1.33 cm\r<BR>\n" );
document.write( "\n" );
document.write( "check: 7.33*5.33=39.07 (approximate because of rounding to two decimal places) </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );