Câu trong ảnh làm như nào các bạn ơi...

Bài 2: a) \( A = (x - 3)(x + 2) + (x - 2)(x - 4) + 11 \) \( = x^2 + 2x - 3x - 6 + x^2 - 4x - 2x + 8 + 11 \) \( = x^2 - x - 6 + x^2 - 6x + 8 + 11 \) \( = 2x^2 - 7x + 13 \) b) \( B = (x + 3)(x - 2) - (x + 1)(x - 4) + 12 \) \( = x^2 - 2x + 3x - 6 - (x^2 - 4x + x - 4) + 12 \) \( = x^2 + x - 6 - x^2 + 3x + 4 + 12 \) \( = 4x + 10 \) c) \( C = 2(x - 3)(x - 1) - (x + 1)(x - 5) + \frac{1}{2} \) \( = 2(x^2 - x - 3x + 3) - (x^2 - 5x + x - 5) + \frac{1}{2} \) \( = 2(x^2 - 4x + 3) - (x^2 - 4x - 5) + \frac{1}{2} \) \( = 2x^2 - 8x + 6 - x^2 + 4x + 5 + \frac{1}{2} \) \( = x^2 - 4x + 11 + \frac{1}{2} \) \( = x^2 - 4x + 11,5 \) d) \( D = 5(x - 3)(x - 3) - 2(x + 1)(x - 5) - \frac{1}{2} \) \( = 5(x^2 - 3x - 3x + 9) - 2(x^2 - 5x + x - 5) - \frac{1}{2} \) \( = 5(x^2 - 6x + 9) - 2(x^2 - 4x - 5) - \frac{1}{2} \) \( = 5x^2 - 30x + 45 - 2x^2 + 8x + 10 - \frac{1}{2} \) \( = 3x^2 - 22x + 55 - \frac{1}{2} \) \( = 3x^2 - 22x + 54,5 \)