help me, giúp tui mấy câu này với

b) (x + 2)² + (1 + x)(1 - x)
= (x + 2)² + (1 - x²)
= x² + 4x + 4 + 1 - x²
= 4x + 5.

c) (x - 3)² + 3(x + 1)²
= (x - 3)(x - 3) + 3(x + 1)(x + 1)
= (x² - 6x + 9) + 3(x² + 2x + 1)
= x² - 6x + 9 + 3x² + 6x + 3
= 4x² + 12.

d) (2 + 3x)(3x - 2) - (3x + 1)²
= 6x + 9x² - 4 - (9x² + 6x + 1)
= 6x + 9x² - 4 - 9x² - 6x - 1
= -5.

e) (x + 5)(x - 2) - (x + 2)²
= (x² + 5x - 2x - 10) - (x² + 4x + 4)
= x² + 3x - 10 - x² - 4x - 4
= -x - 14.

f) (x + 3)(2x - 5) - 2(1 + x)²
= (2x² - 5x + 6x - 15) - 2(1 + 2x + x²)
= 2x² + x - 15 - (2 + 4x + 2x²)
= 2x² + x - 15 - 2 - 4x - 2x²
= -3x - 17.

g) (4x - 1)(4x + 1) - 4(1 - 2x)²
= (16x² - 1) - 4(1 - 4x + 4x²)
= 16x² - 1 - 4 + 16x - 16x²
= 16x - 5.