document.write( "Question 145363: Factor by grouping
\n" ); document.write( "6c squared 11c - 2
\n" ); document.write( "

Algebra.Com's Answer #106049 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\r
\n" ); document.write( "\n" ); document.write( "Looking at \"6c%5E2%2B11c-2\" we can see that the first term is \"6c%5E2\" and the last term is \"-2\" where the coefficients are 6 and -2 respectively.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now multiply the first coefficient 6 and the last coefficient -2 to get -12. Now what two numbers multiply to -12 and add to the middle coefficient 11? Let's list all of the factors of -12:\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Factors of -12:\r
\n" ); document.write( "\n" ); document.write( "1,2,3,4,6,12\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "-1,-2,-3,-4,-6,-12 ...List the negative factors as well. This will allow us to find all possible combinations\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "These factors pair up and multiply to -12\r
\n" ); document.write( "\n" ); document.write( "(1)*(-12)\r
\n" ); document.write( "\n" ); document.write( "(2)*(-6)\r
\n" ); document.write( "\n" ); document.write( "(3)*(-4)\r
\n" ); document.write( "\n" ); document.write( "(-1)*(12)\r
\n" ); document.write( "\n" ); document.write( "(-2)*(6)\r
\n" ); document.write( "\n" ); document.write( "(-3)*(4)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "note: remember, the product of a negative and a positive number is a negative number\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now which of these pairs add to 11? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to 11\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\n" ); document.write( "\n" ); document.write( "
First NumberSecond NumberSum
1-121+(-12)=-11
2-62+(-6)=-4
3-43+(-4)=-1
-112-1+12=11
-26-2+6=4
-34-3+4=1
\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "From this list we can see that -1 and 12 add up to 11 and multiply to -12\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now looking at the expression \"6c%5E2%2B11c-2\", replace \"11c\" with \"-1c%2B12c\" (notice \"-1c%2B12c\" adds up to \"11c\". So it is equivalent to \"11c\")\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"6c%5E2%2Bhighlight%28-1c%2B12c%29%2B-2\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now let's factor \"6c%5E2-1c%2B12c-2\" by grouping:\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"%286c%5E2-1c%29%2B%2812c-2%29\" Group like terms\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"c%286c-1%29%2B2%286c-1%29\" Factor out the GCF of \"c\" out of the first group. Factor out the GCF of \"2\" out of the second group\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"%28c%2B2%29%286c-1%29\" Since we have a common term of \"6c-1\", we can combine like terms\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So \"6c%5E2-1c%2B12c-2\" factors to \"%28c%2B2%29%286c-1%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So this also means that \"6c%5E2%2B11c-2\" factors to \"%28c%2B2%29%286c-1%29\" (since \"6c%5E2%2B11c-2\" is equivalent to \"6c%5E2-1c%2B12c-2\")\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "------------------------------------------------------------\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Answer:\r
\n" ); document.write( "\n" ); document.write( "So \"6c%5E2%2B11c-2\" factors to \"%28c%2B2%29%286c-1%29\"
\n" ); document.write( "
\n" ); document.write( "
\n" );