document.write( "Question 150955: Use a system of equations to solve the word problem. The perimeter of a rectangle is 56 inches, and its area is 192 square inches. What are the dimensions? \n" ); document.write( "
Algebra.Com's Answer #110909 by nerdybill(7384)![]() ![]() You can put this solution on YOUR website! Use a system of equations to solve the word problem. The perimeter of a rectangle is 56 inches, and its area is 192 square inches. What are the dimensions? \n" ); document.write( ". \n" ); document.write( "Let L = length of the rectangle \n" ); document.write( "and W = width of the rectangle \n" ); document.write( ". \n" ); document.write( "For a 'rectangle' we know the following: \n" ); document.write( "perimeter = 2(L+W) \n" ); document.write( "area = LW \n" ); document.write( ". \n" ); document.write( "This then, allows us to derive our \"system of equations\": \n" ); document.write( "56 = 2(L+W) (equation 1) \n" ); document.write( "192 = LW (equation 2) \n" ); document.write( ". \n" ); document.write( "Solving equation 2 for W we get: \n" ); document.write( "192 = LW \n" ); document.write( "192/L = W \n" ); document.write( ". \n" ); document.write( "Substitute the above into equation 1 and solve for L: \n" ); document.write( "56 = 2(L+W) \n" ); document.write( "56 = 2(L + 192/L) \n" ); document.write( "56L = 2(L^2 + 192) \n" ); document.write( "28L = (L^2 + 192) \n" ); document.write( "0 = L^2 - 28L + 192 \n" ); document.write( "Factoring: \n" ); document.write( "0 = (L-16)(L-12) \n" ); document.write( ". \n" ); document.write( "L = {16,12} \n" ); document.write( "Therefore, the dimensions are: \n" ); document.write( "12 inches by 16 inches\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |