(x+1)(x-2)-(x+5)(x+4)=-2 (a+3)(a-b)+(9-5a)(a+1) если a =1 1/4

Решите задачу:

$(x + 1)(x - 2) - (x + 5)(x + 4) = {x}^{2} - 2 x + x - 2 - {x}^{2} - 4x - 5x - 20 = - 10x - 22$

$(a + 3)(a - b) + (9 - 5a)(a + 1) = (1 \frac{1}{4} + 3)(1 \frac{1}{4} - b) + (9 - 5 \times 1 \frac{1}{4} )(1 \frac{1}{4} + 1) = 4 \frac{1}{4} \times 1 \frac{1}{4} - 4 \frac{1}{4} b + (9 - \frac{5 \times 5}{4} ) \times 2 \frac{1}{4} = \frac{17 \times 5}{16} - 4 \frac{1}{4} b + (9 - 6 \frac{1}{4} ) \times \frac{9}{4} = \frac{85}{16} - 4 \frac{1}{4} b + 2 \frac{3}{4} \times \frac{9}{4} = 5 \frac{5}{16} - 4 \frac{1}{4} b + \frac{11 \times 9}{16} = 5 \frac{5}{16} - 4 \frac{1}{4} b + 6\frac{3}{16} = 11 \frac{8}{16} - 4 \frac{1}{4} b = 11.5 - 4.25b$