(i) 686/-3456
686/-3456 = -(∛(2×7×7×7)) / (∛(27×23))
= – (∛(2×73)) / (∛ (27×23))
= – (∛(73)) / (∛(26×23))
= – 7/(2×2×2)
= – 7/8
(v) -39304/-42875
-39304/-42875 = -(∛(2×2×2×17×17×17)) / -(∛(5×5×5×7×7×7))
= – (∛(23×173)) / -(∛(53×73))
= – (2×17)/-( 5×7)
= – 34/-35
= 34/35