Question

Giúp mình bài 2 nhé😘

Answer 1

a)

\(=2\left(x^2+x+1\right)\)

b)

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

c)

\(=x^2-xy+\dfrac{1}{4}y^2-\dfrac{25}{4}y^2\)

\(=\left(x-\dfrac{1}{2}y\right)^2-\left(\dfrac{5}{2}y\right)^2\)

\(=\left(x-\dfrac{1}{2}y-\dfrac{5}{2}y\right)\left(x-\dfrac{1}{2}y+\dfrac{5}{2}y\right)\)

\(=\left(x-3y\right)\left(x+2y\right)\)