Question

1) b^-1/3 : b^2/9
2) 3^-5/2 : 3^-2/3

Answer 1

1) b^-1/3 : b^2/9 =b^(-3/9-2/9)=b^(-5/9):
2) 3^-5/2 : 3^-2/3 =3^(-15/6+4/6)=3^(-11/6)