Answer:

1 = 42, 2 =  48

Step-by-step explanation:

1.

if 18/n =12/28

if multiply 12 by 1.5 and 28 by 1.5

18/n = 18/42

so n = 42

2.

12/16 = n/64

so multiply 12 and 16 by 4

48/64 = n/64

so n = 48