Решите систему неравенств:

а)[tex] \left \{ {{2x+4\ \textgreater \ 0} \atop {x^2+2x-3 \geq 0}} ight. [/tex]

б)[tex] \left \{ {{2x^2 \leq 32} \atop {x^2-4x+3 \geq 0}} ight. [/tex]