|X-3|与(Y+1/2)2互为相反数,则|X-3|+(Y+1/2)2=0而|X-3|≥0 且(Y+1/2)2≥0 所以 |X-3|=0 且(Y+1/2)2=0 即 X-3=0 且Y+1/2=0 所以 X=3 Y=-1/2所以X+Y=3-1/2=5/2希望能帮到你,