Ответ:

Объяснение:

1. 0,6x2y * (-0,5x5y7) = 1,2xy * (-17,5xy) = 21x^2 y^2
2. 0,6x4 * (-10x4)3 = 2,4x * (-40x) 3 = -288 x^2
3. (2a7x12)4 * ax = 168ax * 4ax = 672a^2 x^2
4. (3a2 - 11a + 4) - (6a2 - 2a - 3) = (6a - 11a + 4) - (12a - 2a - 3) = (-5a + 4) - (10a - 3) = -5a + 4 - 10a + 3 = -15a + 7
5. 3a3 * (2a2 - 4) = 9a * (4a - 4) - 36a^2 - 36s
6. (x + 1) (x2 - 3x - 4) = (x + 1) (-x - 4) = -(x+1) (x+4) = -(x^2 + 5x + 4) = -x^2 - 5x - 4
7. (x+5) (2x2 - 2) - 10x2 = (x+5) (4x-2) - 20x = 4x^2 - 18x - 10 - 20x =  4x^2 - 38x - 10