若|x-y+3|与|x+y-1999|互为相反数,求x+2yx−y
若|x-y+3|与|x+y-1999|互为相反数,求x+2yx−y
若|x-y+3|与|x+y-1999|互为相反数,求x+yx−y
若丨x-y+3丨与丨x+y-1995丨互为相反数,则x+2yx−y
若|x-2|与(y+7)2互为相反数,求yx的值.
若|x+y|与|2y-3|互为相反数,求2x+y的值
若|x+y|与|2y-3|互为相反数,求2x+y的值.
若|x十3|与|2y一3|互为相反数,求x+y的值.
若|x-3|与|2y+7|互为相反数,求x+y+3的值 急,
若|X-3|与|Y+2|互为相反数,求x+y+99的值!
若|x+6|与|3y-2|互为相反数,求x+y的值.50分
已知:x2-4x+4与|y-1|互为相反数,则式子(xy−yx)÷(x+y)
若丨x-y+3丨与丨x-y-1999丨互为相反数,求x+y/x-y的值