document.write( "Question 818171: How do you Factor out \r
\n" ); document.write( "\n" ); document.write( "sqrt(4x^4+36x^2+81) to equal 2x^2+9 ? \n" ); document.write( "
Algebra.Com's Answer #492374 by richwmiller(17219)\"\" \"About 
You can put this solution on YOUR website!
foil this 2x^2+9* 2x^2+9 and go back to 4x^4+36x^2+81\r
\n" ); document.write( "\n" ); document.write( "2x^2*2x^2=4x^4
\n" ); document.write( "2x^2*9=18x^2
\n" ); document.write( "9*2x^2=18x^2
\n" ); document.write( "9*9=81
\n" ); document.write( "add them and we have
\n" ); document.write( "4x^4+36x^2+81
\n" ); document.write( "convert
\n" ); document.write( "let y=2x^2
\n" ); document.write( "y^2+18y+81
\n" ); document.write( "we now want factors of 81 which add up to 18
\n" ); document.write( "9*9=81
\n" ); document.write( "9+9=18
\n" ); document.write( "so now we have
\n" ); document.write( "(y+9) but y=2x^2
\n" ); document.write( "so we have
\n" ); document.write( "2x^2+9\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
\n" );