4) $$\sqrt{7\frac{1}{9}} + \sqrt{3\frac{1}{16}} - 0.04\sqrt{90000}$$

$$\qquad 4) \sqrt{7\frac{1}{9}} + \sqrt{3\frac{1}{16}} - 0.04\sqrt{90000} = \sqrt{\frac{64}{9}} + \sqrt{\frac{49}{16}} - 0.04\sqrt{9 \cdot 10000} = \frac{8}{3} + \frac{7}{4} - 0.04 \cdot 3 \cdot 100 = \frac{8}{3} + \frac{7}{4} - 12 = \frac{32 + 21 - 144}{12} = \frac{53 - 144}{12} = \frac{-91}{12} = -7\frac{7}{12}$$ Ответ: $$-7\frac{7}{12}$$