\(\left\{x^2y^2-\dfrac{1}{3}xy+3y\right\}\left(x-3y\right)\)

2. thực hiện phép tính :

a) \(\left(x-y\right)\left(x^2+xy+y^2\right)\)                          b)\(\left(x2\right)-2xy+y2\))\(\left(x-y\right)\)

c)\(\left\{x^2y^2-\dfrac{1}{3xy}+3y\right\}\left(x-3y\right)\)                d) \(\left\{\dfrac{1}{5}x-1\right\}\left(x^2-5x+2\right)\)

c1b

b) (5xy . \(\dfrac{2}{5}\) x² + y ) \(\dfrac{2}{5}\) x y²

c2b

b) x (x² - y ) + x (y² - y ) - x (x² + y²) tại x = \(\dfrac{1}{2}\) và y = \(100\)

c3b

b) 3x (3 - 2x ) + 6x ( x - 1) = 15