10.已知m+n-3(m-2n)=P,-5m-4n+(6m-4n)=Q,则m+n的结果( )
0 278984 278992 278998 279002 279008 279010 279014 279020 279022 279028 279034 279038 279040 279044 279050 279052 279058 279062 279064 279068 279070 279074 279076 279078 279079 279080 279082 279083 279084 279086 279088 279092 279094 279098 279100 279104 279110 279112 279118 279122 279124 279128 279134 279140 279142 279148 279152 279154 279160 279164 279170 279178 366461
| A. | P+Q | B. | -P-Q | C. | P | D. | -Q |