若x.y满足|x-2|+|y+1|=0,且2b+3x=2y+b+7,求b的值
问题描述:
若x.y满足|x-2|+|y+1|=0,且2b+3x=2y+b+7,求b的值
答
若|x-2|+|y+1|=0
则 x-2=0 y+1=0
so x=2 y=-1
当 x=2 y=-1代入2b+3x=2y+b+7
b=-1