Functions question bank (Maths)

Let $f$ be a function such that $f(x)+3 f\left(\frac{24}{x}\right)$ $=4 x, x \neq 0$. Then $f(3)+f(8)$ is equal to

If the domain of the function
$f(x)=\frac{1}{\sqrt{10+3 x-x^2}}+\frac{1}{\sqrt{x+|x|}}$ is $(a, b)$, then $(1+a)^2+b^2$ is equal to :