Question 19: Perform the calculation \(\begin{array}{l} \left( {{x^2}{y^4}{z^3} + 5x{y^3}{z^3} – 4x {y^2}{z^2}} \right):x{y^2}z \end{array}\) we get:

\(\begin{array}{l} \left( {{x^2}{y^4}{z^3} + 5x{y^3}{z^3} – 4x{y^2}{z) ^2}} \right):x{y^2}z\\ = {x^2}{y^4}{z^3}:x{y^2}z + 5x{y^3}{z ^3}:x{y^2}z – 4x{y^2}{z^2}:x{y^2}z\\ = x{y^2}{z^2} + 5y{z^ 2} – 4z \end{array}\)