You're correct, the answer is C.
Given any function of the form

, then the derivative of y with respect to x (

) is written as:

In which

is any constant, this is called the power rule for differentiation.
For this example we have

, first lets get rid of the quotient and write the expression in the form

:

Now we can directly apply the rule stated at the beginning (in which

):

Note that whenever we differentiate a function, we simply "ignore" the constants (we take them out of the derivative).
Answer:
8.1
Step-by-step explanation:
Answer:
i think its b
Step-by-step explanation:
25 because Becky read 45 and Jason read 20
45-20 = 25