若丨x-y+3丨与丨x-y-1999丨互为相反数,求x+y/x-y的值

若丨x-y+3丨与丨x-y-1999丨互为相反数,求x+y/x-y的值 若丨x+y-25丨与根号2x-y-8互为相反数 求3x-4y的值 |x-y+3|与|x+y-1999|互为相反数,求x+y/x-y的值 丨x-y+3丨与丨x+y-1999丨互为相反数,求x-y分之x+y的值. 若丨x+3丨与丨y-1丨互为相反数,求x+y的值. 若丨2x+6丨与丨3-y丨互为相反数,则x/y=? 若丨x+y-3丨+根号2x-y=0,则x-y= 丨x-y+3丨与丨x+y-5丨互为相反数,x=?,y=? 若丨x-y+1丨与丨x+y-2013丨互为相反数,求（x+2y）/（x-y）的值 若丨x+y-1丨与丨x-y+3丨互为相反数,则（x+y）^2007的值为多少? x-y与y/x-y通分 若丨3x-y丨与（2x+y-8）的平方互为相反数,则3x+y等于多少? 若丨2x-2y+7丨与3(x+2y-4)²互为相反数,则x=　y= 若丨x+2丨与丨y-3丨互为相反数,求丨x+y丨的值 若丨x+2丨与丨y-3丨互为相反数,求丨x+y丨的值! 己知丨x-1丨与丨y+3丨互为相反数,求x,y的值. 若丨x+3 丨与丨2y-3 丨互为相反数,求 x+y的值. 若丨2x-3丨与丨y+3丨互为相反数,求x+y的相反数