1)efetue as divisões

a)

(3/5)/(2/3)

=(3/5)*(3/2)

=3*3/(5*2)

=9/10=0,9

b)

(10/7)/(5/14)=(10/7)*(14/5)

=(10/5)*(14/7)

=2 *2 = 4

c)

(8/9)/2 =(8/9)/(2/1)

=(8/9)*(1/2) =8/18=4/9

d)

(2+1/9)/(3+1/6)

(18/9+1/9)/(18/6+1/6)

(19/9)/(19/6)

(19/9)*(6/19)

=(19/19)*(6/9)

=6/9

=2/3