(X+Y)*(5/2)=1200
(x-y)*(10/3)=1200
整理得：
x+y=480①
x-y=360②
解得x=400,y=40能在详细点麽？(X+Y)*(5/2)=1200→x+y=1200*2/5=480(x-y)*(10/3)=1200→x-y=1200*3/10=4360整理得：x+y=480①x-y=360②①+②得：2x=840，x=420把x=420代入得：y=60 解得x=420，y=60前面错了