Let $\int_a^b f(x) dx = 8$ and $\int_a^b (f(x))^2 dx = 19$. Find the following integrals:
$\int_a^b cf(z) dz =$
$\int_a^b (f(x))^2 dx - ( \int_a^b f(x) dx )^2 =$
$\int_{a+3}^{b+3} f(x-3) dx =$ .