Answer:

Step-by-step explanation:
Given


Required
Find PQR
Since both angles are supplementary, we have:

This gives:


Collect Like Terms


Divide through by 10

Substitute 20 for X in 


Answer:
B. Rational functions
Step-by-step explanation:
The partial fraction decomposition is used for functions there are described by fractions, and for which the substitution method is not possible. These are rational functions, in which both the numerator and the denominator are polynomials.
So the correct answer is:
B. Rational functions