document.write( "Question 1187640: A rectangular playground has a walkway around it with a width of x-2. The garden is 36 m by 20 m.
\n" ); document.write( "Find an expression for the combined area of the playground and the walkway around it
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #818651 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
the length becomes 36 + 2 * (x - 2) which becomes 36 + 2x - 4 which becomes 32 + 2x.
\n" ); document.write( "the width becomes 20 + 2 * (x-2) which becomes 20 + 2x - 4 which becomes 16 + 2x.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "the new dimensions are (32 + 2x) for the length and 16 + 2x for the width.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "the combined area is (32 + 2x) * (16 + 2x) = 4x^2 + 96x + 512.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "your equation for the combined area will be 4x^2 + 96x + 512 or (32 + 2x) * (16 + 2x).\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "note that x must be greater than 2, otherwise the combined area will be less than the original area.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "the original area is 36 * 20 = 720
\n" ); document.write( "when x = 2, the combined area will be (32 + 4) * (16 + 4) = 36 * 20 = 720.
\n" ); document.write( "that's breakeven point.
\n" ); document.write( "for the path to have any width, x has to be greater than 2.
\n" ); document.write( "as a practical matter, if you want the path to be at least 2 feet wide, then x should be greater than or equal to 3.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "the following graph shows the relationship.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "as you can see, when x = 3, the combined area is 836 square feet.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "that's because 32 + 2 * 3 = 38 and 16 + 2 * 3 = 22 and 38 * 22 = 836 square feet.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "here's a diagram of what this would look like:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "when x = 3, the value of A in the diagram is x - 2 which becomes 3 - 2 which becomes 1.
\n" ); document.write( "when x = 3, the value of A is 1.
\n" ); document.write( "the length is 36 + 2A = 38.
\n" ); document.write( "the width is 20 + 2A = 22.
\n" ); document.write( "the area is 38 * 22 = 836.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "that's the same value on the graph when x = 3.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );