document.write( "Question 280209: Solve by using quadratic formula x2 – 3x - 10 = 0 \n" ); document.write( "
Algebra.Com's Answer #203648 by richwmiller(17219)\"\" \"About 
You can put this solution on YOUR website!
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"1x%5E2%2B-3x%2B-10+=+0\") has the following solutons:
\n" ); document.write( "
\n" ); document.write( " \"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
\n" ); document.write( "
\n" ); document.write( " For these solutions to exist, the discriminant \"b%5E2-4ac\" should not be a negative number.
\n" ); document.write( "
\n" ); document.write( " First, we need to compute the discriminant \"b%5E2-4ac\": \"b%5E2-4ac=%28-3%29%5E2-4%2A1%2A-10=49\".
\n" ); document.write( "
\n" ); document.write( " Discriminant d=49 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--3%2B-sqrt%28+49+%29%29%2F2%5Ca\".
\n" ); document.write( "
\n" ); document.write( " \"x%5B1%5D+=+%28-%28-3%29%2Bsqrt%28+49+%29%29%2F2%5C1+=+5\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%28-3%29-sqrt%28+49+%29%29%2F2%5C1+=+-2\"
\n" ); document.write( "
\n" ); document.write( " Quadratic expression \"1x%5E2%2B-3x%2B-10\" can be factored:
\n" ); document.write( " \"1x%5E2%2B-3x%2B-10+=+1%28x-5%29%2A%28x--2%29\"
\n" ); document.write( " Again, the answer is: 5, -2.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-3%2Ax%2B-10+%29\"
\n" ); document.write( " \n" ); document.write( "
\n" );