Answer: 4
Step-by-step explanation:
There are 4 terms, 
90,180 is the same as R so it is
-6 1/3 because it looks less than -6.375 which would mean that it is in fact bigger on the number scale.
ANSWER

EXPLANATION
The given fractions are:

We factor to obtain:

We cancel the common factors to get:

We multiply the numerators and also multiply the denominators to get:

Therefore the two fractions simplifies to 