I would believe it to be 22
For this case we have the following system of equations:

Equating the values of y we have:

From here, we can clear the value of x.
We have then:

Then, we look for the value of y.
For this, we substitute x in any of the equations:
Answer:
The ordered pair solution of the system of equations, is given by:
That's false.
Let's see an instance:
10% of 300=30
20% of 100=20
It doesn't work here so it's false
There is no restriction upon the domain, the x values, and is all real numbers or (-oo,+oo)
From such it is clear that the domain also contains all real numbers.
The range of f(x) is (-oo,+oo)