Answers:
A)
C)
Explanation:
Part 1:
We have the followig equation:

Calculating the least common multiple (l.c.m) in the denominator in the left side of the equation, being l.c.m=15:

Solving for the left part of the equation:

Operating with cross product:

Applying the distributive property:

Isolating
:

Dividing numerator and denominator by 11:
Hence, the correct option is A
Part 2:
We have the followig equation:

Operating with cross product:

Isolating
:
Hence, the correct option is C