a/\(4x^2-y^2+4x+1=\left(4x^2+4x+1\right)-y^2=\left(2x+1\right)^2-y^2=\left(2x-y+1\right)\left(2x+y+1\right)\)
b/ \(x^3-x+y^3-y=\left(x^3+y^3\right)-\left(x+y\right)=\left(x+y\right)\left(x^2-xy+y^2\right)-\left(x+y\right)=\left(x+y\right)\left(x^2-xy+y^2-1\right)\)
c/ sai đề?
a, \(4x^2-y^2+4x+1\)
\(=\left(4x^2+4x+1\right)-y^2\)
\(=\left(2x+1\right)^2-y^2\)
\(=\left(2x+1-y\right)\left(2x+1+y\right)\)