Trả lời:
a, \(27a^2b^2-18ab+3=3\left(9a^2b^2-6ab+1\right)=3\left(3ab-1\right)^2\)
b, \(x^2+2xy+y^2-xz-yz\)
\(=\left(x^2+2xy+y^2\right)-z\left(x+y\right)\)
\(=\left(x+y\right)^2-z\left(x+y\right)\)
\(=\left(x+y\right)\left(x+y-z\right)\)
c, \(a^4+a^3-a^2-a\)
\(=\left(a^4+a^3\right)-\left(a^2+a\right)\)
\(=a^3\left(a+1\right)-a\left(a+1\right)\)
\(=a\left(a+1\right)\left(a^2-1\right)\)
\(=a\left(a+1\right)\left(a-1\right)\left(a+1\right)\)
\(=a\left(a+1\right)^2\left(a-1\right)\)
d, \(a^3-b^3+2b-2a\)
\(=\left(a^3-b^3\right)-\left(2a-2b\right)\)
\(=\left(a-b\right)\left(a^2+ab+b^2\right)-2\left(a-b\right)\)
\(=\left(a-b\right)\left(a^2+ab+b^2-2\right)\)
