document.write( "Question 775107: i need help solving the equation graphically and then checking the results algebraially $\"x%5E2-3x=10\"$ \n" ); document.write( "

Algebra.Com's Answer #472667 by sofiyac(983) $\"\"$ $\"About$

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\n" ); document.write( " $\"x%5E2-3x=10\"$
\n" ); document.write( " $\"x%5E2-3x=10\"$ first subtract 10 from each side of the equal sign
\n" ); document.write( " $\"x%5E2-3x-10=0\"$ next pretend instead of 0 on the right side you have y
\n" ); document.write( " $\"x%5E2-3x-10=y\"$ plug in a few values for x (any values) and evaluate, this will give you the matching y's. Here's the table
\n" ); document.write( "x | y
\n" ); document.write( "________
\n" ); document.write( "0 | -10
\n" ); document.write( "-2| 0
\n" ); document.write( "5 | 0
\n" ); document.write( "feel free to do more points, you need quite a few to graph a quadratic but you get the point.
\n" ); document.write( "Now plot these points
\n" ); document.write( " $\"+graph%28+300%2C+200%2C+-10%2C+10%2C+-10%2C+10%2C+x%5E2-3x-10%29+\"$
\n" ); document.write( "As you can see from the graph it crosses x axis at 5 and -2
\n" ); document.write( "Now to check the results plug in the solution one at a time
\n" ); document.write( "check for x=5
\n" ); document.write( " $\"x%5E2-3x=10\"$
\n" ); document.write( " $\"5%5E2-3%2A5=10\"$
\n" ); document.write( " $\"25-15=10\"$
\n" ); document.write( " $\"10=10\"$ left side equals right side so x=5 is a solution
\n" ); document.write( "check for x=-2
\n" ); document.write( " $\"%28-2%29%5E2-3%28-2%29=10\"$
\n" ); document.write( " $\"4%2B6=10\"$
\n" ); document.write( " $\"10=10\"$ left side equals right side so x=-2 is a solution \n" ); document.write( "

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