document.write( "Question 173654: I need confirmation on this problem involving factoring:\r
\n" ); document.write( "\n" ); document.write( "Factor Completely: 16x^4 - 40x^2 + 9 =\r
\n" ); document.write( "\n" ); document.write( "This is what I came up with:\r
\n" ); document.write( "\n" ); document.write( "8(2x^4 - 5x^2) + 1 is this correct? Thanks for any assistance. \n" ); document.write( "

Algebra.Com's Answer #128510 by Fombitz(32388) $\"\"$ $\"About$

You can put this solution on YOUR website!
No that's not correct.
\n" ); document.write( "Let's expand what you got.
\n" ); document.write( " $\"8%282x%5E4+-+5x%5E2%29+%2B+1=16x%5E4+-+20x%5E2+%2B+1\"$
\n" ); document.write( "Let's try this.
\n" ); document.write( "Use a substitution to knock down the degree of the polynomial and hopefully make it look more familiar.
\n" ); document.write( "Let $\"u=x%5E2\"$
\n" ); document.write( "Now substitute this into your equation.
\n" ); document.write( " $\"16x%5E4+-+40x%5E2+%2B+9+=16%28u%5E2%29+-+40u+%2B+9+\"$
\n" ); document.write( " $\"16x%5E4+-+40x%5E2+%2B+9+=16u%5E2+-+40u+%2B+9+\"$
\n" ); document.write( "Now you have a quadratic equation in u and you can look to factor the right hand side,
\n" ); document.write( " $\"16x%5E4+-+40x%5E2+%2B+9=%284u-9%29%284u-1%29\"$
\n" ); document.write( " $\"16x%5E4+-+40x%5E2+%2B+9=%284x%5E2-9%29%284x%5E2-1%29\"$
\n" ); document.write( "You can further factor the right hand sides,
\n" ); document.write( " $\"4x%5E2-9=%282x-3%29%282x%2B3%29\"$
\n" ); document.write( " $\"4x%5E2-1=%282x-1%29%282x%2B1%29\"$
\n" ); document.write( ".
\n" ); document.write( ".
\n" ); document.write( ".
\n" ); document.write( " $\"16x%5E4+-+40x%5E2+%2B+9=%284x%5E2-9%29%284x%5E2-1%29\"$
\n" ); document.write( " $\"16x%5E4+-+40x%5E2+%2B+9=%282x-1%29%282x%2B1%29%282x%2B3%29%282x-3%29\"$ \n" ); document.write( "

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