Question

[Nguyễn Minh Chiến]

Cứu 

Answer 1

[Nguyễn Minh Chiến]

đôi ơn anh

Answer 2

[Hà Quang Minh]

Bài 2:

\(a,\left(\dfrac{x}{2}-4\right)^2\\ =\dfrac{x^2}{4}-2\cdot\dfrac{x}{2}\cdot4+4^2\\ =\dfrac{x^2}{4}-4x+16\\ b,\left(\dfrac{1}{y}+\dfrac{y}{x}\right)^2\\ =\dfrac{1}{y^2}+\dfrac{2}{x}+\dfrac{y^2}{x^2}\\ c,\left(5x-8y\right)\left(5x+8y\right)\\ =25x^2-64y^2\\ d,\left(x+y-2\right)^2\\ =x^2+y^2+4+2xy-4x-4y\)