计算:2x-{-3y+[3x-2(3x-y)]},其中x=-1,y=-1/5.先化简,再求值

来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/23 03:30:37
计算:2x-{-3y+[3x-2(3x-y)]},其中x=-1,y=-1/5.先化简,再求值计算:2x-{-3y+[3x-2(3x-y)]},其中x=-1,y=-1/5.先化简,再求值计算:2x-{-

计算:2x-{-3y+[3x-2(3x-y)]},其中x=-1,y=-1/5.先化简,再求值
计算:2x-{-3y+[3x-2(3x-y)]},其中x=-1,y=-1/5.
先化简,再求值

计算:2x-{-3y+[3x-2(3x-y)]},其中x=-1,y=-1/5.先化简,再求值
2x-{-3y+[3x-2(3x-y)]}
=2x+3y-[3x-2(3x-y)]
=2x+3y-3x+6x+2y
=5x+5y
当x=-1,y=-1/5时
5x+5y=5*(-1)+5*(-1/5)=-5-1=-6

满意答案是错的吧

2x-{-3y+[3x-2(3x-y)]}
=2X-(-3Y+3X-6X+2Y)
=2X-(-Y-3X)
=2X+Y+3X
=5X+Y
=5*1-1/5
=4.8

计算:2x-{-3y+[3x-2(3x-y)]},其中x=-1,y=-1/5.
2x-{-3y+[3x-2(3x-y)]}
=2x-{-3y+[3x-6x+2y]}
=2x-{-3y-3x+2y}
=2x-{-y-3x}
=2x+y+3x
=5x+y
其中:x=-1,y=-1/5.
=5*(-1)+(-1/5)
=-5-1/5
=-26/5