√576a¹² ------- 256b²⁶

$$\sqrt{\frac{576a^{12}}{256b^{26}}} = \sqrt{\frac{36 a^{12} }{16 b^{26} }} = \frac{\sqrt{36 a^{12}}}{\sqrt{16 b^{26}}} = \frac{6 a^6}{4 b^{13}} = \frac{3 a^6}{2 b^{13}}$$

Ответ: $$\frac{3 a^6}{2 b^{13}}$$