document.write( "Question 200226: solve\r
\n" ); document.write( "\n" ); document.write( "2x^2 - 3x - 2 = 0 using quadratic formula
\n" ); document.write( "

Algebra.Com's Answer #150530 by Edwin McCravy(20054)\"\" \"About 
You can put this solution on YOUR website!
solve
\n" ); document.write( "\"2x%5E2+-+3x+-+2+=+0\" using quadratic formula
\n" ); document.write( "
\r\n" );
document.write( "It could be solved easier by factoring like this:\r\n" );
document.write( "\r\n" );
document.write( "\"2x%5E2+-+3x+-+2+=+0\"\r\n" );
document.write( "\r\n" );
document.write( "\"%28x-2%29%282x%2B1%29=0\"\r\n" );
document.write( "\r\n" );
document.write( "\"x-2=0\" or \"x=2\"\r\n" );
document.write( "\r\n" );
document.write( "\"2x%2B1=0\" or \"2x=-1\" or \"x=-1%2F2\"\r\n" );
document.write( "\r\n" );
document.write( "But you are told specifically to do it by the\r\n" );
document.write( "quadratic formula.  So this is what we do\r\n" );
document.write( "there:\r\n" );
document.write( "\r\n" );
document.write( "The solution to\r\n" );
document.write( "\r\n" );
document.write( "\"ax%5E2%2Bbx%2Bc=0\" is\r\n" );
document.write( "\r\n" );
document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"\r\n" );
document.write( "\r\n" );
document.write( "You must memorize that!\r\n" );
document.write( "\r\n" );
document.write( "In your problem\r\n" );
document.write( "\r\n" );
document.write( "\"2x%5E2+-+3x+-+2+=+0\"\r\n" );
document.write( "\r\n" );
document.write( "\"a=2\", \"b=-3\", \"c=-2\"\r\n" );
document.write( "\r\n" );
document.write( "So substituting:\r\n" );
document.write( "\r\n" );
document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\"x+=+%283+%2B-+sqrt%28+9%2B16+%29%29%2F4+\"\r\n" );
document.write( "\r\n" );
document.write( "\"x+=+%283+%2B-+sqrt%2825%29%29%2F4+\"\r\n" );
document.write( "\r\n" );
document.write( "\"x+=+%283+%2B-+5%29%2F4+\"\r\n" );
document.write( "\r\n" );
document.write( "That's two solutions\r\n" );
document.write( "\r\n" );
document.write( "1.   \"x+=+%283+%2B+5%29%2F4+=+8%2F4+=+2\"\r\n" );
document.write( "\r\n" );
document.write( "2.   \"x+=+%283+-+5%29%2F4+=+-2%2F4+=+-1%2F2\"\r\n" );
document.write( "\r\n" );
document.write( "So you see we get the same solutions as we did \r\n" );
document.write( "when we factored it.\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" ); document.write( "
\n" );