Question

daca n.m-p.m=320 si n-p=16

Answer 1

dam factor comun 
 m ( n-p) = 320
m*16 = 320
m = 320:16
m = 20

Answer 2

$nm-pm=320 \\ n-p=16 \\ m=? \\ nm-pm=320 \\ m(n-p)=320 \\ 16m=320 \\ m=320:16 \\ \boxed{m=20}$