多項式的乘法

$$2x^2\cdot\left(-3x^2\right)=?$$  

$$2x\cdot3x=?$$  

$$3x\left(2x^3\right)=?$$  

$$x^2\cdot x^3=?$$  

$$x^2\left(x-1\right)=?$$  

$$x\left(x+1\right)=?$$  

$$x\cdot\left(2x\right)=?$$  

$$\left(x^2-1\right)\cdot x$$  

$$\left(x+1\right)\left(x-1\right)=?$$  

$$\left(x-1\right)^2=?$$  

$$\left(x+1\right)^2=?$$  

$$\left(x+2\right)^2=?$$  

$$\left(x-2\right)^2=?$$  

$$\left(x+2\right)\left(x-2\right)=?$$  

$$\left(x+6\right)^2=?$$   

$$\left(x+4\right)^2=?$$  

$$\left(x+8\right)^2=?$$   

$$\left(x-7\right)^2=?$$  

$$\left(x-5\right)^2=?$$  

$$\left(x-3\right)^2=?$$  

$$\left(x+3\right)\left(x-3\right)=?$$  

$$\left(x-4\right)\left(x+4\right)=?$$  

$$\left(x-6\right)\left(x+6\right)=?$$