3*4^x-11*2^x=4 помогите решить срочно

Решите задачу:

$3 \times {4}^{x} - 11 \times {2}^{x} = 4 \\ 3 \times {4}^{x} -11 \times {2}^{x} - 4 = 0 \\ {2}^{x } = y \\ 3 {y}^{2} - 11y - 4 = 0 \\ d = {11}^{2} + 4 \times 4 \times 3 = 121 + 48 = 169 = {13}^{2} \\ y1 = \frac{11 + 13}{2 \times 3} = 4 \\ y2 = \frac{11 - 13}{6} = \frac{ - 2}{6 } = - \frac{1}{3} ne \: podhodit \\ {2}^{x} = 4 \\ {2}^{x } = {2}^{2} \\ x = 2$