document.write( "Question 963559: find the x-intercepts of the parabola with vertex (-3,16) and y-intercept (0,-20).
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Algebra.Com's Answer #588668 by Fombitz(32388) $\"\"$ $\"About$

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In vertex form,
\n" ); document.write( " $\"y=a%28x%2B3%29%5E2%2B16\"$
\n" ); document.write( "Use the y-intercept,
\n" ); document.write( " $\"-20=a%280%2B3%29%5E2%2B16\"$
\n" ); document.write( " $\"-20=9a%2B16\"$
\n" ); document.write( " $\"9a=-36\"$
\n" ); document.write( " $\"a=-4\"$
\n" ); document.write( "So then,
\n" ); document.write( " $\"y=-4%28x%2B3%29%5E2%2B16\"$
\n" ); document.write( "For x-intercepts, set $\"y=0\"$ and solve for $\"x\"$ ,
\n" ); document.write( " $\"0=-4%28x%2B3%29%5E2%2B16\"$
\n" ); document.write( " $\"4%28x%2B3%29%5E2=16\"$
\n" ); document.write( " $\"%28x%2B3%29%5E2=4\"$
\n" ); document.write( " $\"x%2B3=0+%2B-+2\"$
\n" ); document.write( " $\"x=3+%2B-+2\"$
\n" ); document.write( " $\"x=1\"$ and $\"x=5\"$
\n" ); document.write( "(1,0) and (5,0) \n" ); document.write( "

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