document.write( "Question 907608: the parabola y=ax2+k passes through the points (-1,3) and (3,-13). find the values of a and k \n" ); document.write( "

Algebra.Com's Answer #550460 by reviewermath(1029) $\"\"$ $\"About$

You can put this solution on YOUR website!
the parabola $\"y=ax%5E2%2Bk\"$ passes through the points (-1,3) and (3,-13). find the values of a and k.
\n" ); document.write( "Equation 1: $\"a%28-1%29%5E2+%2B+k+=+3\"$
\n" ); document.write( "Equation 2: $\"a%283%29%5E2+%2B+k+=+-13\"$
\n" ); document.write( "Subtract the 1st equation from the 2nd equation, the result is
\n" ); document.write( " $\"8a+=+-16\"$ , divide both sides by 8
\n" ); document.write( "a = -2, substitute into Equation 1 and solve for k:
\n" ); document.write( "-2 + k = 3
\n" ); document.write( "k = 5
\n" ); document.write( "Answers: a = -2 and k= 5\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );