a, (2x+1) (3x-5) - (2x-1)²- 2x² + 10
= 6x² - 10x + 3x - 5 - (4x²- 4x + 1) - 2x²+ 10
= 6x² - 10x + 3x - 5 - 4x²+ 4x - 1 - 2x²+ 10
= -3x +4
b, 4 (2x+3) (2x-3) - (4x+3)²+ 2x + 1
= 4 (4x²- 9) - (4x+3)²+ 2x + 1
= 16x² - 36 - (16x² + 24x + 9) + 2x + 1
= 16x² - 36 - 16x² - 24x - 9 + 2x + 1
= -22x - 44
c, (3x+4)²- (3x+2) (4x-5)+3x² + 11
= 9x² + 24 +16 - (12x²- 15x + 8x - 10)+3x²+ 11
= 9x²+ 24x + 16 − 12x²+ 15x − 8x + 10 + 3x²+ 11
= 31x+37
d, (2x+1)³- (x+2) (3x+2)²+ x³+ 8
= 8x³+ 12x²+ 6x +1- (x+2) (9x²+ 12x +4)+ x³+ 8
= 8x³+ 12x²+ 6x +1− (9x³+ 12x²+ 4x + 18x²+ 24x +8)+x³+ 8
= 8x³+ 12x²+ 6x +1 − 9x³− 12x²− 4x − 18x²− 24x − 8 + x³+ 8
= −18x²− 22x + 1
- Chúc bn học tốt.