(27)2/3 + (625)1/4 - (8)2/3

[tex]27 \frac{2}{3} + 625 \frac{1}{4} - 8 \frac{2}{3} \\ = \frac{83}{3} + \frac{2501}{4} - \frac{26}{3} \\ = \frac{332 + 7503 - 104}{12} \\ = \frac{7731}{12} \\ = 644 \frac{3 \div 3}{12 \div 3} \\ = 644 \frac{1}{4} [/tex]