ПОМОГИТЕЕЕЕ СРОЧНО ОЧЕЕЕНь!!!!

Решите задачу:

$1)a)3 {x}^{2} - 3xy + 3xy - 3 {y}^{2} = \\ = 3 {x}^{2} - 3 {y}^{2} \\ \\ b)4ab - 6 {b}^{2} - 15 {b}^{2} + 9ab = \\ = 13ab - 21 {b}^{2}$
$2)a) - 88 + 16x + 40 = 15x - 12 \\ 16x - 15x = 48 - 12 \\ x = 36$
$b)7(x + 14) - 5(6x + 1) = 35 \\ 7x - 98 - 30x - 5 = 35 \\ - 23x = 35 + 103 \\ - 23x = 138 \\ x = 138 \div ( - 23) \\ x = - 6$