Ok, first you have to know that 0.25 is one fourth. Finding one fourth of 60 is the first step. 1/4 of 60 is 15. Now, add 3 to 15, and you have your answer! The answer is 18 pounds.
Not sure but you can figure it out.
a. Note that
is continuous for all
. If
attains a maximum at
, then
. Compute the derivative of
.

Evaluate this at
and solve for
.




To ensure that a maximum is reached for this value of
, we need to check the sign of the second derivative at this critical point.

The second derivative at
is negative, which indicate the function is concave downward, which in turn means that
is indeed a (local) maximum.
b. When
, we have derivatives

Inflection points can occur where the second derivative vanishes.




Then we have three possible inflection points when
,
, or
.
To decide which are actually inflection points, check the sign of
in each of the intervals
,
,
, and
. It's enough to check the sign of any test value of
from each interval.




The sign of
changes to either side of
and
, but not
. This means only
and
are inflection points.
Answer:

Step-by-step explanation:
The answer is the first option, <-20, -42>.
We can find this by first finding what -2u would equal by multiplying <5, 6> by -2. This gives us <-10, -12>.
Then we need to find out what 5v is equal to, by multiplying <-2, -6> by 5 to get <-10, -30>.
Now that we know what -2u and 5v are, we can substitute them into the equation and get
<-10, -12> + <-10, -30>, which we can split up into -10 - 10 = -20, and -12 - 30 = -42, so your final answer is <-20, -42>.
I hope this helps!