Answer
a.$\quad m(x)=5(x^{2}+1)$
b.$\quad \mathbb{R}$ (all reals)
c.$\quad 10$
Work Step by Step
$a.$
$m=cf$ is the function specified by $m(x)=cf(x)$
$m(x)=5(x^{2}+1)$
$b.$
See Note on Domains p.70-71
Domain of $cf$: Same as the domain of f.
Domain of m: $\mathbb{R}$ (all reals)
c.
$m(1)=5(1^{2}+1)=5(2)=10$