a/
\(=x^2\left(x^2+2x+1\right)=x^2\left(x+1\right)^2\)
b/
\(=x^3+3x^2y+3xy^2+y^3-\left(x+y\right)\)
\(=\left(x+y\right)^3-\left(x+y\right)\)
\(=\left(x+y\right)\left[\left(x+y\right)^2-1\right]\)
\(=\left(x+y\right)\left(x+y+1\right)\left(x+y-1\right)\)
c/
Đề sai, câu này ko phân tích được
d/
\(=a^3\left(a^2+1\right)-\left(a^2+1\right)\)
\(=\left(a^3-1\right)\left(a^2+1\right)\)
\(=\left(a-1\right)\left(a^2+1\right)\left(a^2+a+1\right)\)
e.
\(=x^4+4x^2+4-4x^2\)
\(=\left(x^2+2\right)^2-\left(2x\right)^2\)
\(=\left(x^2-2x+2\right)\left(x^2+2x+2\right)\)
f.
\(=4x^4+4x^2y^2+y^4-4x^2y^2\)
\(=\left(2x^2+y^2\right)^2-\left(2xy\right)^2\)
\(=\left(2x^2-2xy+y^2\right)\left(2x^2+2xy+y^2\right)\)
g.
\(=81x^4+36x^2+4-36x^2\)
\(=\left(9x^2+2\right)^2-\left(6x\right)^2\)
\(=\left(9x^2-6x+2\right)\left(9x^2+6x+2\right)\)
