Ответ:

1) (x-3)2-9 = (x-3)(x-3) - 9 = x^2 - 6x + 9 - 9 = x^2 - 6x

2) 12y-(x-6)² = 12y - (x^2 - 12x + 36) = -x^2 + 12x + 12y + 36

3) (2a-3b)2-(3a+2b)2 = 4a^2 - 12ab + 9b^2 - 9a^2 - 12ab - 4b^2 = -5a^2 - 24ab + 5b^2

4) (2x-3y)²+(4x+2y)² = 4x^2 - 12xy + 9y^2 + 16x^2 + 16xy + 4y^2 = 20x^2 + 13y^2

5) (x-5)²-x(x+3) = x^2 - 10x + 25 - x^2 - 3x = -13x + 25

6) (6a-b)2- (9a - b)(4a+2b) = 36a^2 - 12ab + b^2 - (36a^2 - 9ab - 18b^2) = -27a^2 + 21ab + 20b^2

7) 3x(5+x)² - x(3x-6)² = 3x(25 + 10x + x^2) - x(9x^2 - 36x + 36) = 75x + 27x^2

8) 0,6(ab-1)²+1,4(ab + 2)² = 0,6(a^2b^2 - 2ab + 1) + 1,4(a^2b^2 + 4ab + 4) = 2a^2b^2 + 3,6ab + 6,4

Объяснение: