Tìm x ( n ) biết .   X ( z ) = 2 z 2 − 5 z z 2 − 5 z + 6

$x\left(n\right)=2{}^n\cdot u\left(n\right)+3{}^n\cdot u\left(n\right)\left|z\right|<3$

$\text{x}\left(\text{n}\right)=2{}^{\text{n}}\cdot \text{u}\left(\text{n}\right)+3{}^{\text{n}}$

$x\left(n\right)=2{}^n\cdot u\left(n\right)+3{}^n\cdot u\left(n\right)2<\left|z\right|<3$

$\text{x}\left(\text{n}\right)=2{}^{\text{n}}\cdot \text{u}\left(\text{n}\right)+3{}^{\text{n}}\cdot \text{u}\left(\text{n}\right)\left|\text{z}\right|>3$