Question1. Simplify with positive exponents: a) $\sqrt{\frac{(25 x)^{\frac{1}{2}}\left(8 x^{2}\right)^{\frac{1}{3}}}{40 x^{\frac{1}{6}}}}$ b) $\frac{\left(8 x^{3} y^{4}\right)^{2}\left(-25 x^{3} y^{2}\right)^{3}}{\left(-10 x^{3} y^{2}\right)^{6}}$