Алгебра 7 класс Карточка ~2. ① Упростите выражение: 1) (x+2) (x+14)-2x (3-4x) 2) (9+5) (9-2)+(a-4)(9+6) 3) (y-9) (3y-1)-(2y+1) (5y-7) 4) (4x-1) (4x-3)-(2x-10) (8x+1)

1) $$(x+2)(x+11) - 2x(3-4x) = x^2 + 11x + 2x + 22 - 6x + 8x^2 = 9x^2 + 7x + 22$$

2) $$(a+5)(a-2) + (a-4)(a+6) = a^2 - 2a + 5a - 10 + a^2 + 6a - 4a - 24 = 2a^2 + 5a - 34$$

3) $$(y-9)(3y-1) - (2y+1)(5y-7) = 3y^2 - y - 27y + 9 - (10y^2 - 14y + 5y - 7) = 3y^2 - 28y + 9 - 10y^2 + 9y + 7 = -7y^2 - 19y + 16$$

4) $$(4x-1)(4x-3) - (2x-10)(8x+1) = 16x^2 - 12x - 4x + 3 - (16x^2 + 2x - 80x - 10) = 16x^2 - 16x + 3 - 16x^2 + 78x + 10 = 62x + 13$$

Ответ: 1) $$9x^2 + 7x + 22$$; 2) $$2a^2 + 5a - 34$$; 3) $$-7y^2 - 19y + 16$$; 4) $$62x + 13$$