document.write( "Question 341864: The width of a rectangle is 8 less than twice its length. If the area of the rectangle is 200 cm^2, what is the length of the diagonal? \n" ); document.write( "
Algebra.Com's Answer #244812 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! The width of a rectangle is 8 less than twice its length. \n" ); document.write( " If the area of the rectangle is 200 cm^2, what is the length of the diagonal? \n" ); document.write( ": \n" ); document.write( "Let x = the length \n" ); document.write( "then \n" ); document.write( "(2x-8) = the width \n" ); document.write( "and \n" ); document.write( "x(2x-8) = 200; the area \n" ); document.write( "A quadratic equation \n" ); document.write( "2x^2 - 8x - 200 = 0 \n" ); document.write( "Simplify, divide by 2 \n" ); document.write( "x^2 - 4x - 100 = 0 \n" ); document.write( "Find x using the quadratic formula \n" ); document.write( " \n" ); document.write( "In this equation: a=1; b=-4; c=-100 \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( " \n" ); document.write( "The positive solution is what we want here \n" ); document.write( " \n" ); document.write( "x = \n" ); document.write( "x = 12.2 is the length \n" ); document.write( "then \n" ); document.write( "2(12.2) - 8 = 16.4 is the width \n" ); document.write( ": \n" ); document.write( "Check solution by finding the area: 12.2 * 16.4 = 200.1 ~ 200, close enough \n" ); document.write( ": \n" ); document.write( "Find the diagonal (d) \n" ); document.write( "d = \n" ); document.write( "c = 20.44 cm is the diagonal \n" ); document.write( " \n" ); document.write( " |