document.write( "Question 135536: Solve \"x%5E3%2B2x%5E2-11x-12%3C0\" \n" ); document.write( "
Algebra.Com's Answer #99300 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\"x%5E3%2B2x%5E2-11x-12=0\" Set the left side equal to zero. \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "When we use a graphing calculator, we find that the solutions are \"x=-4\", \"x=-1\" and \"x=3\". So that means that the inequality \"x%5E3%2B2x%5E2-11x-12%3C0\" factors to \"%28x%2B4%29%28x%2B1%29%28x-3%29%3C0\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now plot the critical values on a number line\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"number_line%28+600%2C+-10%2C+10%2C+-4%2C-1%2C3+%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So let's evaluate a point that is to the left of (which is the left most endpoint). Let's evaluate the value \"x=-5\"\r
\n" ); document.write( "\n" ); document.write( " \r
\n" ); document.write( "\n" ); document.write( " Start with the given inequality\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Plug in \"x=-5\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Evaluate and simplify\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Since is true, this means that one part of the solution in interval notation is \r
\n" ); document.write( "\n" ); document.write( "-----------------------------------------------\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now let's test a point that is in between the critical values and \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Start with the given inequality\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Plug in \"x=-2\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Evaluate and simplify\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Since is false, this means that the interval does not work. So that means that this interval is not in the solution set and can be ignored.\r
\n" ); document.write( "\n" ); document.write( "-----------------------------------------------\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now let's test a point that is in between the critical values and \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Start with the given inequality\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Plug in \"x=1\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Evaluate and simplify\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Since is true, this means that one part of the solution in interval notation is \r
\n" ); document.write( "\n" ); document.write( "-----------------------------------------------\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So let's evaluate a point that is to the right of (which is the right most endpoint). Let's evaluate the value \"x=4\"\r
\n" ); document.write( "\n" ); document.write( " \r
\n" ); document.write( "\n" ); document.write( " Start with the given inequality\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Plug in \"x=4\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Evaluate and simplify\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Since is false, this means that the interval does not work. So that means that this interval is not in the solution set and can be ignored.\r
\n" ); document.write( "\n" ); document.write( "-----------------------------------------------\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Answer:\r
\n" ); document.write( "\n" ); document.write( "So the solution set in interval notation is
\n" ); document.write( "
\n" );