Simplify and express the result in power notation with positive exponent. (i) `(-4)^5 -: (-4)^8` (ii) `(1/(2^3))^2` (iii) `(-3)^4 xx (5/3)^4` (iv) `(3^(-7) -: 3^(-10)) xx 3^(-5)` (v) `2^(-3) xx (-7)^(-3)`