Thực hiện phép tính A = 3x^2 y^3 (x^4 y^2)(− 1/5 x^3 y)

a) \(A = 3{x^2}{y^3}\left( {{x^4}{y^2}} \right)\left( { - \frac{1}{5}{x^3}y} \right)\)

\( = 3{x^6}{y^5}\left( { - \frac{1}{5}{x^3}y} \right)\)

\( = \frac{{ - 3}}{5}{x^9}{y^6}\).

b) \[B = \left( {10{x^4}{y^3} - 15{x^5}{y^4} + 35{x^4}{y^2}} \right):5{x^2}{y^2}\]

\[ = 10{x^4}{y^3}:\left( {5{x^2}{y^2}} \right) - 15{x^5}{y^4}:\left( {5{x^2}{y^2}} \right) + 35{x^4}{y^2}:\left( {5{x^2}{y^2}} \right)\]
\[ = 2{x^2}y - 3{x^3}{y^2} + 7{x^2}\].

c) \(C = 4x{y^2}\left( {2{x^2} - {y^2}} \right) - 3x\left( {{x^2}{y^2} - {y^4}} \right)\)

\( = \left( {8{x^3}{y^2} - 3{x^3}{y^2}} \right) + \left( {3x{y^4} - 4x{y^4}} \right)\)

\( = 8{x^3}{y^2} - 4x{y^4} - 3{x^3}{y^2} + 3x{y^4}\)

\( = 5{x^3}{y^2} - x{y^4}\).