Question

Answer 1

Bài 1:

a: \(=\left(x+\dfrac{1}{2}y\right)^2-16=\left(x+\dfrac{1}{2}y-4\right)\left(x+\dfrac{1}{2}y+4\right)\)

b: \(=x\left(x^2+xy-2y^2\right)=x\left(x^2+2xy-xy-2y^2\right)\)

\(=x\left[x\left(x+2y\right)-y\left(x+2y\right)\right]\)

\(=x\left(x+2y\right)\left(x-y\right)\)

c: \(=\left(x-y\right)\left(x+y\right)+9\left(y-x\right)=\left(x-y\right)\left(x+y-9\right)\)

d: \(=\left(x-y\right)\left(x+y\right)+3\left(x+y\right)=\left(x+y\right)\left(x-y+3\right)\)