document.write( "Question 1061379: X squared minus 3x equals 28 by factoring \n" ); document.write( "

Algebra.Com's Answer #676154 by KMST(5328) $\"\"$ $\"About$

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TRADITIONAL APPROACH:
\n" ); document.write( " $\"x%5E2-3x=28\"$
\n" ); document.write( " $\"x%5E2-3x-28=0\"$
\n" ); document.write( "The factored form will look like this:
\n" ); document.write( " $\"%28x%2B%22___%22%29%28x%2B%22___%22%29=0\"$
\n" ); document.write( "You look for a pair of factors of $\"-28\"$ ,
\n" ); document.write( "whose product is $\"-28\"$ ,
\n" ); document.write( "and whose sum is $\"-3\"$ .
\n" ); document.write( "Since $\"4%2A7=28\"$ and $\"-7%2B4=-3\"$ ,
\n" ); document.write( "you fill the blanks with $\"-7\"$ and $\"4\"$ to get
\n" ); document.write( " $\"highlight%28%28x-7%29%28x%2B4%29=0%29\"$ .
\n" ); document.write( "So, $\"system%28x-7=0%2C%22or%22%2Cx%2B4=0%29\"$ ---> $\"highlight%28system%28x=7%2C%22or%22%2Cx=-4%29%29\"$
\n" ); document.write( "
\n" ); document.write( "AN ALTERNATE IDEA:
\n" ); document.write( " $\"x%5E2-3x=28\"$
\n" ); document.write( " $\"x%28x-3%29=28\"$
\n" ); document.write( "I am looking for two numbers
\n" ); document.write( "whose product is $\"28\"$ ,
\n" ); document.write( "and whose difference is $\"3\"$ .
\n" ); document.write( " $\"system%28x=7%2Cx-3=4%29\"$ works,
\n" ); document.write( "and so does $\"system%28x=-4%2Cx-3=-7%29\"$ .
\n" ); document.write( "So, $\"highlight%28system%28x=7%2C%22or%22%2Cx=-4%29%29\"$
\n" ); document.write( " \n" ); document.write( "

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