[tex]3x^2+4x-4=0 \\ \Delta=b^2-4ac \\ \Delta=4^2-4\cdot3(-4)\\ \Delta=16+48\\ \Delta=64 \\ \\ \boxed{X_1= \frac{-b+ \sqrt{\Delta} }{2a} = \frac{-4+8}{2\cdot3} = \frac{4}{6} = \frac{2}{3} } \\ \\ \boxed{X_2= \frac{-b-\sqrt{\Delta} }{2a} = \frac{-4-8}{2\cdot3} = \frac{-12}{6} = -2} } \\ \\ \\ \boxed{\boxed{S=\{-2 ; \frac{2}{3} \}}}[/tex]
