document.write( "Question 141902: How do you find the term that should be added to the expression to make a perfect square trinomial?\r
\n" ); document.write( "\n" ); document.write( "x^2 + 11x
\n" ); document.write( "x^2 + 4/5x\r
\n" ); document.write( "\n" ); document.write( "how? \n" ); document.write( "

Algebra.Com's Answer #103364 by Earlsdon(6294) $\"\"$ $\"About$

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To make the trinomials perfect square trinomials, you must add the square of half the x-coeffecient, as long as the x^2-coefficient is 1.\r
\n" ); document.write( "\n" ); document.write( " $\"x%5E2%2B11x\"$ The $\"x%5E2\"$ -coefficient is 1 so add the square of half the x-coefficient. Add $\"%2811%2F2%29%5E2+=+121%2F4\"$ to get:
\n" ); document.write( " $\"x%5E2%2B11x%2B121%2F4\"$
\n" ); document.write( "Check:
\n" ); document.write( " $\"x%5E2%2B11x%2B121%2F4+=+%28x%2B11%2F2%29%28x%2B11%2F2%29\"$ = $\"%28x%2B11%2F2%29%5E2\"$
\n" ); document.write( "Likewise for:
\n" ); document.write( " $\"x%5E2%2B%284%2F5%29x\"$ Add $\"%28%281%2F2%29%284%2F5%29%29%5E2+=+%284%2F10%29%5E2\"$ = $\"16%2F100+=+4%2F25\"$ to get:
\n" ); document.write( " $\"x%5E2%2B%284%2F5%29x%2B4%2F25\"$ \n" ); document.write( "

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