document.write( "Question 1055475: A rectangular poster needs to have 2700 square centimeters of printed material surrounded by margins. The margins on the left and right edges need to be 4 cm thick, and the margins on the top and bottom edges need to be 3 cm thick. What should the dimensions of the overall poster be in order to minimize the total area? \n" ); document.write( "
Algebra.Com's Answer #670719 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
let \"+A+\" = the total area of printed material
\n" ); document.write( "plus margins in cm2
\n" ); document.write( "Let \"+x+\" = one of the dimensions of printed material
\n" ); document.write( "Let \"+y+\" = the other dimension of printed material
\n" ); document.write( "(1) \"+A+=+%28+x+%2B+2%2A3+%29%2A%28+y+%2B+2%2A4+%29+\" cm2
\n" ); document.write( "------------------------------------
\n" ); document.write( "(1) \"+A+=+%28+x+%2B+6+%29%2A%28+y+%2B+8+%29+\" cm2
\n" ); document.write( "(2) \"+x%2Ay+=+2700+\" cm2
\n" ); document.write( "------------------------------------
\n" ); document.write( "(2) \"+y+=+2700%2Fx+\"
\n" ); document.write( "Plug (2) into (1)
\n" ); document.write( "(1) \"+A+=+%28+x+%2B+6+%29%2A%28+2700%2Fx+%2B+8+%29+\"
\n" ); document.write( "(1) \"+A+=+2700+%2B+16200%2Fx+%2B+8x+%2B+48+\"
\n" ); document.write( "(1) \"+A+=+16200%2Fx+%2B+8x+%2B+2748+\"
\n" ); document.write( "-------------------------------------
\n" ); document.write( "Is this a calculus problem? That would be the only
\n" ); document.write( "way I know how to solve this.
\n" ); document.write( "Set the derivative of \"+A+\" with respect to \"+x+\" = \"+0+\"
\n" ); document.write( "\"+-16200%2Fx%5E2+%2B+8+=+0+\"
\n" ); document.write( "\"+16200%2Fx%5E2+=+8+\"
\n" ); document.write( "\"+x%5E2+=+16200%2F8+\"
\n" ); document.write( "\"+x%5E2+=+2025+\"
\n" ); document.write( "\"+x+=+45+\"
\n" ); document.write( "----------------
\n" ); document.write( "(2) \"+y+=+2700%2Fx+\"
\n" ); document.write( "(2) \"+y+=+2700%2F45+\"
\n" ); document.write( "(2) \"+y+=+60+\"
\n" ); document.write( "----------------------
\n" ); document.write( "\"+x+%2B+6+=+45+%2B+6+\"
\n" ); document.write( "\"+x+%2B+6+=+51+\"
\n" ); document.write( "and
\n" ); document.write( "\"+y+%2B+8+=+60+%2B+8+\"
\n" ); document.write( "\"+y+%2B+8+=+68+\"
\n" ); document.write( "----------------------------------
\n" ); document.write( "The dimensions of the overall
\n" ); document.write( "poster to minimize area is 51 x 68
\n" ); document.write( "----------------------------------
\n" ); document.write( "Here's the plot of \"+A%28x%29+\":
\n" ); document.write( "\"+graph%28+400%2C+400%2C+-30%2C+100%2C+-500%2C+5000%2C+16200%2Fx+%2B+8x+%2B+2748+%29+\"
\n" ); document.write( "This looks OK -
\n" ); document.write( "\"+A%28+51+%29+=+51%2A68+\"
\n" ); document.write( "\"+A%28+51+%29+=+3468+\" looks like a minimum\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );