Answer:
The value of k =3
Step-by-step explanation:
We need to solve this equation to become in standard form to find the value of k.

The given standard form is:

Comparing it with 
The value of k =3
Answer:
The Domain.
Step-by-step explanation:
That is the Domain. For example the domain of the function √x is the set
{x : x ≥ 0}.
First, subtract 63 from 75 to find out how much it decreased.
75 - 63 = 12
Divide 12 by 75.
12 / 75 = 0.16
In percents, that is 16%.
He spent 16% less this month.
Hope this helps!