Question

1.Thực hiện các phép tính sau:

1) 3xy ( x³ - 3y

2) ( x² - 1 ) (x² + 2x)

3) ( 2x - 1) (3x + 2 ) ( 3-x) 

4)( x+3) ( x² +3x - 5 )

5) ( x+ 1) ( x² – x + 1)

6) ( 2x³ – 3x -1 ) ( 5x+ 2)

7) ( x² – 2x + 3) ( x-4)

8) -2x³y ( 2x² – 3y + 5yz )

9) ( x – 2y ) ( x² y² – xy + 2y )

10) 2/5 xy( x²y – 5x + 10y )  

11) 2/3 x² y ( 3xy – x² + y )

12) ( x – y ) (x² + xy + y² ) 

 

Answer 1

2: \(=x^4+2x^3-x^2-2x\)

3: \(=\left(6x^2+x-2\right)\left(3-x\right)\)

\(=18x^2-6x^3+3x-x^2-6+2x\)

\(=-6x^3+17x^2+5x-6\)

4: \(=x^3+3x^2-5x+3x^2+9x-15\)

\(=x^3+6x^2+4x-15\)

5: =x^3+1