Помогите пожалуйста) 1.Выполните действия А)(2а²-2+7)-(9а²-5а) Б)4х(6х-х в пятой степени)...

Решите задачу:

$1) \\ a)(2 {a}^{2} - 2 + 7) - (9 {a}^{2} - 5a) = (2 {a}^{2} + 5) - 9 {a}^{2} + 5a = \\ 2 {a}^{2} + 5 - 9 {a}^{2} + 5a = - 7 {a}^{2} + 5 + 5a$
$\\ b)4x \times (6 - x - {x}^{5} ) = 24x - 4 {x}^{2} - 4 {x}^{6} = \\ - 4 {x}^{6} - 4 {x}^{2} + 24x$
$2)a)2xy - 3x {y}^{2} = xy(2 - 3y)$
$b)3b + 6 {b}^{3} = 3b(1 + 2 {b}^{2})$
$v)4 \times (x - y) - a \times (x - y) = (x - y) \times (4 - a)$
$g)a \times (a - 6) + 2 \times (6 - a) = a \times (a - 6) - 2 \times (a - 6) = (a - 6) \times (a + 2)$
$d) {y}^{9} + {y}^{4} = {y}^{4} \times ( {y}^{5} + 1)$
$3)7 - 4 \times (3x - 1) = 5 \times (1 - 2x) \\ 7 - 12x + 4 = 5 - 10x \\ 11 - 12x = 5 - 10x \\ - 12 + 10x = 5 - 11 \\ - 2x = - 6 \\ x = 3$
$4)5 {a}^{2} - 2a = 0 \\ a \times (5a - 2) = 0 \\ a = 0 \\ 5a - 2 = 0 \\ a1 = 0 \\ a2 = \frac{2}{5} = 0.4$