Question

na expressão a+b/ab para a=1/3 e b=2/5

Answer 1

a+b
ab

a=1/3
b=2/5

a + b =  1 + 2 =   5+6 ==> 11
             3    5        15         15

Answer 2

1/3+2/5 /1/3 x 2/5

1/3+2/5 = 11/15

1/3 x 2/5 = 2/15

11/15 /2/15 =  11/15 x 15/2 =165/30 = 11/2