∵(x+y-5)²+√（x-y+1）=0∴x+y-5=0，x-y+1=0得x=2，y=3故√（-4x+3y）=√1=1
解：由题意知：x+y-5=0 x-y+1=0 解得：x=2,y=3 ∴跟下-4x+3y=跟下1=1
