Answer:
(C) 10m + 7n - 14
Step-by-step explanation:
[Q-R]+[S-T] =[(7m+3n)-(11-2m)]+[(n+5)-(-m-3n+8)]=
=[7m+3n-11+2m] + [n+5+m+3n-8]=[9m+3n-11] + [4n+m - 3]=
=9m+3n-11+4n+m-3=10m + 7n - 14
