Answer:

Step-by-step explanation:
First, notice that:



We proceed to use the chain rule to find
using the fact that
to find their derivatives:

Because we know
then:
We substitute in what we had:

Now we put in the values
in the formula:

Because of what we supposed:

And we operate to discover that:


and this will be our answer
Answer:
£140 increased by 5% is £147.00
Answer:
The correct answer would be 15.5 or C.
Answer:
25GB was used that month
Step-by-step explanation:
Here, we want to calculate the GB used for the month.
Since we have $59.99 for 20GB, then the extra that brought the bill to $75.99 must have been from the beyond charges.
The extra charges is thus $75.99 - $59.99 = $20
Now, since $4 is charged as extra and we have a total of $20, the number of extra GB is thus 20/4 = 5
So the total GB for that month is 20 + 5 = 25GB