Prove that limxa+[f(x)+g(x)]=L+K if limxa+f(x)=L and limxa+g(x)=K.

Problem: 

Prove that
limxa+[f(x)+g(x)]=L+K
if
limxa+f(x)=L
and
limxa+g(x)=K.

Answer: 

It is true that limxa+[f(x)+g(x)]=L+K if limxa+f(x)=L and limxa+g(x)=K.