29.32 срочнопомогите!

$a.\\(3x+8)(x+12)\ \textgreater \ 3(x+12)^2\\3x^2+36x+8x+96\ \textgreater \ 3(x^2+24x+144)\\3x^2+44x+96\ \textgreater \ 3x^2+72x+432\\3x^2+44x-3x^2-72x\ \textgreater \ 432-96\\-28x\ \textgreater \ 336\\-x\ \textgreater \ \frac{336}{28}\\-x\ \textgreater \ 12|:(-1)\\x\ \textless \ -12$
xЄ(-беск; -12)
$b.\\(2x+5)(8x-15)\ \textless \ (4x-3)^2\\16x^2-30x+40x-75\ \textless \ 16x^2-24x+9\\16x^2-30x+40x-16x^2+24x\ \textless \ 75+9\\34x\ \textless \ 84\\\\x\ \textless \ \frac{84}{34}\\\\x\ \textless \ \frac{42}{17}\\\\x\ \textless \ 2\frac{8}{17}$
xЄ(-беск; $2\frac{8}{17})$