[tex]( \frac{1}{126}) \frac{ - 1}{3} +128 \frac{4}{7 } + 27 \frac{2}{3} [/tex]

(1/216)^-1/3 + 128^4/7 -27^2/3
= (1/6^3)^-1/3 + (2^7)^4/7 - (3^3)^2/3
= (6^-3)^-1/3 + 2^4 - 3^2
= 6^1 + 2^4 - 3^2
= 6 + 16 - 9
= 13