Объяснение:

[tex] {(2x + 4)}^{2} = 11 {x}^{2} + 1 \\ 4 {x}^{2} + 16x + 16 = 11 {x}^{2} + 1 \\ 4 {x}^{2} - 11 {x}^{2} + 16x + 16 - 1 = 0 \\ - 7 {x}^{2} + 16x + 15 = 0 \\ 7 {x}^{2} - 16x - 15 = 0 \\ d = {( - 16)}^{2} - 4 \times 7 \times ( - 15) = 256 + 420 = 676 \\ x1 = \frac{ - ( - 16) - 26}{2 \times 7} = \frac{ - 10}{14} = - \frac{5}{7} \\ x2 = \frac{16 + 26}{14} = \frac{42}{14} = 3[/tex]