1) phan tich thanh nhan tu
a) x^2 + 4x - y^2 +4
b) 3x^2 + 6xy + 3y^2 - 3z^2
c) x^2 - 2xy + y^2 - z^2 + 2zt - t^2
d) x^3 - 2x^2 + x
e) 2x^2 + 4x + 2 - 2y^2
g) 2xy - x^2 - y^2 + 16
f) x^2 - 3x + 2
h) x^2 + x - 6
i) x^2 + 5x + 6
k) x^3 - 7x - 6
canh nhanh cang tot a ^^
h) x^2 + x
a) \(x^2+4x-y^2+4\)
\(=\left(x+2\right)^2-y^2\)
\(=\left(x+2-y\right)\left(x+2+y\right)\)
b) \(3x^2+6xy+3y^2-3z^2\)
\(=3\left(x^2+2xy+y^2-z^2\right)\)
\(=3\left[\left(x+y\right)^2-z^2\right]\)
\(=3\left(x+y-z\right)\left(x+y+z\right)\)