Suppose f(x)=3x+1\displaystyle {f{{\left({x}\right)}}}=-{3}{x}+{1}, while a=10\displaystyle {a}=-{10} and b=2\displaystyle {b}={2}. Compute the following:

A.) f(a)+f(b)=\displaystyle {f{{\left({a}\right)}}}+{f{{\left({b}\right)}}}=

B.) f(a)f(b)=\displaystyle {f{{\left({a}\right)}}}-{f{{\left({b}\right)}}}=