Помогите с алгеброй, срочно, очень надо!

$- 1\ \textless \ \frac{2a+1}{3}\ \textless \ 5\\\\-1*3\ \textless \ \frac{2a+1}{3}*3\ \textless \ 5*3\\\\-3\ \textless \ 2a+1\ \textless \ 15 \\\\-3-1\ \textless \ 2a+1-1\ \textless \ 15-1\\\\-4\ \textless \ 2a\ \textless \ 14\\\\-2\ \textless \ a\ \textless \ 7$
a ∈ (- 2 ; 7)

$-7\ \textless \ \frac{3a-2}{2}\ \textless \ 2\\\\-7*2\ \textless \ \frac{3a-2}{2}*2\ \textless \ 2*2\\\\-14\ \textless \ 3a-2\ \textless \ 4\\\\-14+2\ \textless \ 3a-2+2\ \textless \ 4+2\\\\-12\ \textless \ 3a\ \textless \ 6 \\\\-4\ \textless \ a\ \textless \ 2$
a ∈ (- 4 ; 2)

$-1 \leq \frac{8-x}{4} \ \textless \ 4\\\\-1*4 \leq \frac{8-x}{4} *4\ \textless \ 4*4\\\\-4 \leq 8-x\ \textless \ 16\\\\-4-8 \leq 8-x-8\ \textless \ 16-8\\\\-12 \leq -x\ \textless \ 8\\\\-12*(-1) \leq -x*(-1) \ \textless \ 8*(-1)\\\\-8\ \textless \ x \leq 12$
Ответ : при x ∈ (- 8 ; 12]

$-1 \leq \frac{2-x}{5} \ \textless \ 4\\\\-1*5 \leq \frac{2-x}{5} *5\ \textless \ 4*5\\\\-5 \leq 2-x\ \textless \ 20\\\\-5-2 \leq 2-x-2\ \textless \ 20-2\\\\-7 \leq -x\ \textless \ 18\\\\-7*(-1) \leq -x*(-1)\ \textless \ 18*(-1)\\\\-18\ \textless \ x \leq 7$
Ответ: при x ∈ (- 18 , 7]