12:00 to 1:30 , that is 90 minutes
if 35 people enter each minute then it should be multiplied by the number of minutes
that being said, 90 x 35 = 3,150 people are in the stadium at 1:30
45
Find ten percent of 50 by moving the decimal point left once and subtract it from 50
The Lagrangian,
has critical points where its partial derivatives vanish:
tells us 
, so that
Then with 
, we get
and 
tells us
Then there are two critical points, 
. The critical point with the negative 
-coordinates gives the maximum value, 
.
