Question

Решите пожалуйста, даю 30 баллов, буду благодарен!

Answer 1

1

$2x( {x}^{4} - 5 {x}^{3} + 3) =2 {x}^{5} - 10 {x}^{4} + 6x$

1. $(y + 2)(3y - 5) = 3 {y}^{2} - 5y + 6y - 10 = 3 {y}^{2} + y + 10$
2. $(7x - 3y)(2x + 5y) = 14 {x}^{2} + 35xy - 6xy - 15 {y}^{2} = 14 {x}^{2} + 29xy - 15 {y}^{2}$
3. $(x - 1)( {x}^{2} - x - 2) = {x}^{3} - {x}^{2} - 2x - {x}^{2} + x + 2 = - 2 {x}^{2} + {x}^{3} - x + 2$

2

1. $15xy - 25 {y}^{2} = 5y(3x - 5y)$
2. $12 {a}^{5} - 4 {a}^{4} = 4 {a}^{4} (3a - 1)$
3. $6a - 6y + ab - by = 6(a - y) + b(a - y) = (a - y)(6 + a)$

3

$7 {x}^{2} + 21x = 0 \\ 7x(x + 3) = 0 \\ 7x = 0 \\ x + 3 = 0 \\ x = 0 \\ x = - 3$

Ответ: 0;-3