\(\frac{-1}{3}x^5y\left(\frac{-3}{7}\right)xy^2z=\left(\frac{-1}{3}.\frac{-3}{7}\right)x^5yxy^2z=\frac{1}{7}x^6y^3z\)
\(-\frac{1}{3}x^5y\left(-\frac{3}{7}\right)xy^2z\)
\(=\left[\left(-\frac{1}{3}\right)\cdot\left(-\frac{3}{7}\right)\right]x^5xyy^2z\)
\(=\frac{1}{7}x^6y^3z\)