√（x+y-199）=√（199-x-y）∵x+y-199≥0,199-x-y≤0∴x+y-199=0∴x+y=199∵ {2x+3y-m=0 -------①{3x+2y+1-m=0 --------②①+②:5(x+y)+1-2m=05(x+y)=2m-1∴2m-1=5(x+y)=995∴m=498