[tex]f(x) = {x}^{2} + x - 2 \\ f( - 2x) = ( - 2x) ^{2} + ( - 2x) - 2 \\ = 4 {x}^{2} - 2x - 2 \\ \\ g(x) = 3f( - 2x) \\ g(x) = 3(4 {x}^{2} - 2x - 2) \\ = 12 {x}^{2} - 6x - 6 \\ = 6(2x + 1)(x - 1) \\ \\ g(x) = \sqrt{3f( - 2x)} \\ = \sqrt{3(4 {x}^{2} - 2x - 2)} \\ = \sqrt{12 {x}^{2} - 6x - 6} \\ = \sqrt{6(2x + 1)(x - 1)} \\ x = - \frac{1}{2} ,1[/tex]
From what I understood from the question I answered, I'm not sure about it , I hope this helps you ^_^
