Question

sd

Answer 1

1) \(9x^2+9x-y^2-3y=\left(3x+y\right)\left(3x-y\right)-y\left(3+y\right)=kobtlàm\)

2) \(A=x^3-6xy-y^3=\left(x-y\right)\left(x^2+xy+y^2\right)-6xy=2x^2+2xy+2y^2-6xy\)

\(=2x^2-4xy+2y^2=\left(\sqrt{2}x-\sqrt{2}y\right)^2=\left[\sqrt{2}\left(x-y\right)\right]^2=\left(2\sqrt{2}\right)^2=8\)

3) \(E=\left(x-1\right)^4-x^2\left(x^2+6\right)+4x\left(x^2+1\right)\)

\(=\left(x^2-2x+1\right)\left(x^2-2x+1\right)-x^4-6x^2+4x^3+4x\)

\(=x^4-2x^3+x^2-2x^3+4x^2-2x+x^2-2x+1-x^4-6x^2+4x^3+4x\)

\(=1\)

Vậy biểu thức E không phụ thuộc biến x

Answer 2

- Cảm ơn nha :))