若x和y满足‖x+2‖+‖y+1‖=0,则3x+2y=b+7,求b=?(‖表示绝对值符号)

问题描述:

若x和y满足‖x+2‖+‖y+1‖=0,则3x+2y=b+7,求b=?(‖表示绝对值符号)

‖x+2‖+‖y+1‖=0,因为绝对值恒大于0; 所以:x=-2; y=-1; 3x+2y=b+7=-7; 解得:b=-21; 祝你学业进步!