Simplify each of the following:
(a) $2 a b-4 a c+b a-2 c b+3 b a$
(b) $3 x^{2} y z-z x^{2} y+4 y x z^{2}-2 x^{2} z y+3 z^{2} y x-3 z y^{2}$
(c) $c^{p} \times c^{-q} \div c^{-2}$
(d) $\frac{\left(x^{\frac{1}{2}}\right)^{-\frac{2}{3}} \div\left(y^{3}\right)^{2} \times\left(x^{\frac{3}{5}}\right)^{-\frac{5}{3}}}{\left(x^{\frac{1}{4}}\right)^{-1} \times\left(y^{\frac{1}{3}}\right)^{6}}$