document.write( "Question 266830: the perimetere of a rectangle is 20 in and the area is 16sq in. find the diminsions \n" ); document.write( "
Algebra.Com's Answer #196112 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! the perimeter of a rectangle is 20 in \n" ); document.write( "2L + 2W = 20 \n" ); document.write( "Simplify, divide by 2 \n" ); document.write( "L + W = 10 \n" ); document.write( "W = (10-L); this form for substitution \n" ); document.write( ": \n" ); document.write( "and the area is 16sq in. \n" ); document.write( "L * W = 16 \n" ); document.write( "Replace W with (10-L) \n" ); document.write( "L * (10-L) = 16 \n" ); document.write( "-L^2 + 10L - 16 = 0; our old friend, the quadratic equation \n" ); document.write( "Multiply by -1, change the signs, makes it easier to factor \n" ); document.write( "L^2 - 10L + 16 = 0 \n" ); document.write( "Factor \n" ); document.write( "(L-8)(L-2) = 0 \n" ); document.write( "Two solutions \n" ); document.write( "L = 8; then W = 2 \n" ); document.write( "L = 2: then W = 8 \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "Check solution in perimeter equation \n" ); document.write( "2(8) + 2(2) = 20 \n" ); document.write( ":\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "find the dimensions: 8 in by 2 in \n" ); document.write( " |