Question

1 phần 3 x +2y 1 phầ 9 y bình - 2 phần 3 xy +4y bình giúp vs ạ

Answer 1

đề

Answer 2

viết lại đi khó nhìn quá 

Answer 3

=(1/3 . x + 2y)((1/3 .x)^2 -1/3 .x.2y +(2y)^2)

=(1/3 .x)^3 +(2y)^3

Answer 4

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

\(=\left(\dfrac{1}{3}.x+2y\right)\left(\dfrac{1}{3}x+2y\right)^2\)

\(=\left(\dfrac{1}{3}.x+2y\right)^3\)

Answer 5

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

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

\(=\left[\left(\dfrac{1}{3}x\right)^2-\left(2y\right)^2\right]\left(\dfrac{1}{3}-2y\right)\)

\(=\left(\dfrac{1}{9}x^2-4y^2\right)\left(\dfrac{1}{3}-2y\right)\)