document.write( "Question 167735: A partial solution set is given. Find the complete solution set.\r
\n" ); document.write( "\n" ); document.write( "x^3+3x^2-13x-15=0;{-1}
\n" ); document.write( "

Algebra.Com's Answer #123644 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Note: since -1 is a given solution, this means that \"x%2B1\" is a given factor\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Since -1 is a given zero, we can use with synthetic division where -1 is the test zero.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Set up the synthetic division table by placing the test zero in the upper left corner and placing the coefficients of the polynomial to the right of the test zero.\n" ); document.write( "\n" ); document.write( "
-1|13-13-15
|
\r
\n" ); document.write( "\n" ); document.write( "Start by bringing down the leading coefficient (it is the coefficient with the highest exponent which is 1)\r
\n" ); document.write( "\n" ); document.write( "\n" ); document.write( "\n" ); document.write( "
-1|13-13-15
|
1
\r
\n" ); document.write( "\n" ); document.write( " Multiply -1 by 1 and place the product (which is -1) right underneath the second coefficient (which is 3)\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
-1|13-13-15
|-1
1
\r
\n" ); document.write( "\n" ); document.write( " Add -1 and 3 to get 2. Place the sum right underneath -1.\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
-1|13-13-15
|-1
12
\r
\n" ); document.write( "\n" ); document.write( " Multiply -1 by 2 and place the product (which is -2) right underneath the third coefficient (which is -13)\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
-1|13-13-15
|-1-2
12
\r
\n" ); document.write( "\n" ); document.write( " Add -2 and -13 to get -15. Place the sum right underneath -2.\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
-1|13-13-15
|-1-2
12-15
\r
\n" ); document.write( "\n" ); document.write( " Multiply -1 by -15 and place the product (which is 15) right underneath the fourth coefficient (which is -15)\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
-1|13-13-15
|-1-215
12-15
\r
\n" ); document.write( "\n" ); document.write( " Add 15 and -15 to get 0. Place the sum right underneath 15.\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
-1|13-13-15
|-1-215
12-150
\r
\n" ); document.write( "\n" ); document.write( "Since the last column adds to zero, we have a remainder of zero. This means \"x%2B1\" is a factor of \"x%5E3+%2B+3x%5E2+-+13x+-+15\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now lets look at the bottom row of coefficients:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The first 3 coefficients (1,2,-15) form the quotient\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x%5E2+%2B+2x+-+15\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So \"%28x%5E3+%2B+3x%5E2+-+13x+-+15%29%2F%28x%2B1%29=x%5E2+%2B+2x+-+15\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Basically \"x%5E3+%2B+3x%5E2+-+13x+-+15\" factors to \"%28x%2B1%29%28x%5E2+%2B+2x+-+15%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now simply solve \"x%5E2+%2B+2x+-+15=0\" to find the remaining two solutions (I'll let you do that)
\n" ); document.write( "
\n" ); document.write( "
\n" );