For the answer to the question above asking to e<span>xplain why the events "getting a black marble" and "getting a red marble" are mutually exclusive.
</span>A marble can have only one color, so you cannot choose a marble that is both black and red. Therefore the events are mutually exclusive (cannot happen simultaneously)
will be increasing on the intervals where
and decreasing wherever
. Local extrema occur when
and the sign of
changes to either side of that point.
is positive when
is between -4 and some number between -2 and -1, and also 2 (exclusive) and 4, so you can estimate that
is increasing on the intervals [-4, -2] and (2, 4].
is negative when
is between some number between -2 and -1, up to some number less than 2. So
is decreasing on the interval [-1, 1].
You then have two possible cases for extrema occurring. The sign of
changes for some
between -2 and -1, and again to either side of
.
To solve any equation, you do whatever you need to do
to wind up with the unknown quantity all alone on one side.
BUT ... whatever you do to one side of the equation, you must
also do to the other side.
Here, we have the
he original equation: -15 = a/5
Multiply each side by 5 : -75 = a
and bada-bing, THERE's the solution !
