document.write( "Question 828560: The area of a rectangle is 28 sq inches. The length is 8 more than thrice the width. Find the length and the width. \n" ); document.write( "
Algebra.Com's Answer #499429 by LinnW(1048)![]() ![]() You can put this solution on YOUR website! area = L*W \n" ); document.write( "28=(3W+8)(W) \n" ); document.write( "28 = 3W^2+8W \n" ); document.write( "subtract 28 from each side \n" ); document.write( "0 = 3W^2+8W-28 \n" ); document.write( "The product of the outer coefficients is 3*(-28) = -84 \n" ); document.write( "The product of 14 and -6 is -84 and their sum is 8 \n" ); document.write( "so we can solve by parts \n" ); document.write( "3W^2 +14W -6W -28 = 0 \n" ); document.write( "W(3W + 14) -2(3W + 14) + 0 \n" ); document.write( "(W - 2)(3W + 14) = 0 \n" ); document.write( "So W = 2 or W = -14/3 \n" ); document.write( "We cannot have a negative length so W = 2 \n" ); document.write( "length = (3W+8) = (3*3 + 8 ) = 17 \n" ); document.write( "width = 2 and length = 17 \n" ); document.write( " \n" ); document.write( " |