document.write( "Question 838361: The equation is h(t)= -16t^2+50t+4. (h for feet and t for seconds). The question is When will the ball be 40 feet above the ground. I plugged 40 into h(t), subtracted it and inserted it into the other side. I factored but got t=9/8 and t=2. I do not think I am supposed to have two positive numbers. \n" ); document.write( "

Algebra.Com's Answer #505023 by josgarithmetic(39617) $\"\"$ $\"About$

You can put this solution on YOUR website!
?
\n" ); document.write( "?\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"-16t%5E2%2B50t%2B4=40\"$
\n" ); document.write( " $\"-16t%5E2%2B50t%2B4-40=0\"$
\n" ); document.write( " $\"-16t%5E2%2B50t-36=0\"$
\n" ); document.write( " $\"8t%5E2-25t%2B18=0\"$
\n" ); document.write( "-
\n" ); document.write( "discriminant is $\"highlight%2825%5E2-4%2A8%2A18=49%29\"$
\n" ); document.write( " $\"t=%2825%2B-+7%29%2F%282%2A8%29\"$ , TWO POSITIVE VALUES.
\n" ); document.write( "-
\n" ); document.write( "Continuing, $\"t=%2825%2B-+7%29%2F16\"$
\n" ); document.write( " $\"t=9%2F8\"$ or $\"t=2\"$
\n" ); document.write( "-
\n" ); document.write( "What goes up also comes down. \n" ); document.write( "

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