None of those describe this function.
It's not a constant function, because it is not equal to a constant (something that isn't a variable)
It doesn't show direct variation, because it can't be represented in the form
y = kx.
It isn't an absolute value function because the absolute value isn't taken anywhere.
If it was an absolute value function it would look something like this:

It isn't a greatest integer function, because the greatest integer isn't taken anywhere.
If it was a greatest integer function it would look something like this:

Are you sure you typed that question right?
Answer:
Decimal Form: 0.875 Fraction Form: 7/8
Step-by-step explanation:
7 divided by 8 is 0.875 and another way to write seven eighths is 7/8
I hope this helps
First replace y with 15.
1/5x-10=30
Then just solve from there.
x=200