高一数学题(x+2的绝对值)+(Y
(x+2的绝对值)+(Y-1的绝对值)=1,求X+Y
|x+2|+|y-1|=1 当|x+2|取正,|y-1|取正时 =>x+2+y-1=1 => x+y=0; 当|x+2|取正,|y-1|取负时 =>x+2+1-y=1 => x-y=-2; 当|x+2|取负,|y-1|取正时 =>-x-2+y+1=1 => x-y=-4; 当|x+2|取负,|y-1|取负时 =>-x-2+1-y=1 => x+y=2