Question

Thực hiện phép tính

a)\(\left(x^2+\frac{2}{5}y\right)\cdot\left(x^2+\frac{2}{5}y\right)\)

b)\(\left(x^2-\frac{1}{3}\right)\cdot\left(x^4+\frac{1}{3}x^2+\frac{1}{9}\right)\)

                         Giúp mình nha mọi người 

 

Answer 1

\(\left(x^2+\frac{2}{5}y\right)\left(x^2+\frac{2}{5}y\right)=x^4+\frac{4}{5}x^2y+\frac{4}{25}y\)

b\(\left(x^2-\frac{1}{3}\right)\left(x^4+\frac{1}{3}x^2+\frac{1}{9}\right)=\left(x^2-\frac{1}{3}\right)^3-x^2-\frac{1}{3}\)

Answer 2

=(x²-1/3)³-x²+1/3 nhé

Answer 3

cám ơn bn nha

Answer 4

Mà bạn có thể giải cụ thể giúp mình đc ko

Answer 5

\(\left(x^2+\frac{2}{5}y\right)\left(x^2+\frac{2}{5}y\right)=\left(x^2+\frac{2}{5}y\right)^2=\left(x^2\right)^2+2.x.\frac{2}{5}.y+\left(\frac{2}{5}y\right)^2=x^4+\frac{4}{5}xy+\frac{4}{5}y^2\)

\(\left(x^2-\frac{1}{3}\right)\left(x^4+\frac{1}{3}x^2+\frac{1}{9}\right)\)

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

\(=\left(x^2\right)^3-\left(\frac{1}{3}\right)^3\)