document.write( "Question 1036503: I need help with this: 3x^2+9x-30=0 Thanks \n" ); document.write( "

Algebra.Com's Answer #651183 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"+3x%5E2+%2B+9x+-+30+=+0+\"$
\n" ); document.write( "You can complete the square to find roots
\n" ); document.write( "Divide both sides by $\"+3+\"$
\n" ); document.write( " $\"+x%5E2+%2B+3x+-+10+=+0+\"$
\n" ); document.write( " $\"+x%5E2+%2B+3x+=+10+\"$
\n" ); document.write( "Take 1/2 of the coefficient of the $\"+x+\"$ term,
\n" ); document.write( "square it and add to both sides
\n" ); document.write( " $\"+x%5E2+%2B+3x+%2B+%283%2F2%29%5E2+=+10+%2B+%283%2F2%29%5E2+\"$
\n" ); document.write( " $\"+x%5E2+%2B+3x+%2B+9%2F4++=+10+%2B+9%2F4+\"$
\n" ); document.write( " $\"+x%5E2+%2B+3x+%2B+9%2F4++=+49%2F4+\"$
\n" ); document.write( " $\"+%28+x+%2B+3%2F2+%29%5E2+=+%28+7%2F2+%29%5E2+\"$
\n" ); document.write( "Take the square root of both sides
\n" ); document.write( " $\"++x+%2B+3%2F2+=+7%2F2+\"$
\n" ); document.write( " $\"+x+=+4%2F2+\"$
\n" ); document.write( " $\"+x+=+2+\"$
\n" ); document.write( "-------------
\n" ); document.write( "and, taking the negative square root of $\"+49%2F4+\"$
\n" ); document.write( " $\"+x+%2B+3%2F2+=+-7%2F2+\"$
\n" ); document.write( " $\"+x+=+-10%2F2+\"$
\n" ); document.write( " $\"+x+=+-5+\"$
\n" ); document.write( "The roots are $\"+x+=+2+\"$ and $\"+x+=+-5+\"$
\n" ); document.write( "---------------
\n" ); document.write( "Here's the plot of the given equation:
\n" ); document.write( " $\"+graph%28+400%2C+600%2C+-7%2C+4%2C+-38%2C+5%2C+3x%5E2+%2B+9x+-+30++%29+\"$ \n" ); document.write( "

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