Respuesta :

factor them

14m²n²=2*7*m*m*n*n
18mn=2*3*3*m*n
2m²n³=2*m*m*n*n*n
2mn=2*m*n
2mn²=2*m*n*n
2m²n³=2*m*m*n*n*n

what is common to all of them?
2*m*n

answer is 2mn is common to all of them
that is the gcf