Answer
a) $98$ b) $49$
c) $4$ and d) $4$
Work Step by Step
a) $(f \space o \space g)(4)=f(g(4)); \\ f(49) =(2)(49)=98$
b) $(g \space o \space f)(2)=g(f(2)); \\ g(4) =48+1=49$
c) $(f \space o \space f)(1)=f(f(1)); \\ f(2) =(2)(2)=4$
d) $(g \space o \space g)(0)=f(g(0)); \\ g(1)=3+1=4$
Hence, a) $98$ b) $49$
c) $4$ and d) $4$