How do you add mixed number with different denominations

He that is measured at 220° is a reflex angle. the opposite angle is obtuse. find the measure of obtuse .

If f(x) = x+8 and g(x) = 4x- 3, find (f+g)(x)

Jason went to an arcade to play video games. he paid $2 for every 11 tokens he bought. he spent a total of $16 on tokens. which equation can be used to determine, t, the number lf tokens jason bought