document.write( "Question 1115552: The area of a rectangular wall of a barn is 80 square feet. Its length is 12 feet longer than twice its width? \n" ); document.write( "
Algebra.Com's Answer #730391 by addingup(3677)\"\" \"About 
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width : W
\n" ); document.write( "length: L
\n" ); document.write( "L = W+12
\n" ); document.write( "----------------------
\n" ); document.write( "W x (W+12) = 80
\n" ); document.write( "W^2+12W = 80
\n" ); document.write( "The coefficient of W^1 is 1
\n" ); document.write( "The coefficient of 12W is 12, an even number
\n" ); document.write( "Thus, we'll complete the squares to solve.
\n" ); document.write( "Divide 12/2=6; square 6 and add to both sides:
\n" ); document.write( "W^2+12W+36 = 116 now we have a perfect square on the left.
\n" ); document.write( "Factor, remember that when x^2+bx+c is a perfect square you can factor it as (x+b/2)^2. So let's do it:
\n" ); document.write( "(W+6)^2 = 116
\n" ); document.write( "sqrt(W+6)^2 = sqrt116
\n" ); document.write( "x+6 = 2(sqrt29)-6 = 4.77
\n" ); document.write( "x+6 = -2(sqrt29)-6 = -16.77
\n" ); document.write( ":
\n" ); document.write( "we are not looking for a negative number, so try 4.77:
\n" ); document.write( "4.77*(4.77+12) = 80 Correct, you have the correct answer.
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\n" ); document.write( "Happy learning,
\n" ); document.write( "John\r
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