(A^2*b^1/2)^1/4/a^1/2*b^9/8

1) (a² *b^(1/2))^1/4 =a^(2/4) *b^(1/8) =a^(1/2) *b^(1/8)2) (a^(1/2) *b^(1/8)) /(a^(1/2) *b^(9/8)) =a^(1/2 -1/2) *b^(1/8 -9/8) =a^0 *b^(-8/8) =1 *b^(-1) =1/b