如果(3x²-2)-(3x²-y)=-2,那么代数式(x+y)+3(x-y)-4(x-y-2)的值是

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/18 00:33:56

如果(3x²-2)-(3x²-y)=-2,那么代数式(x+y)+3(x-y)-4(x-y-2)的值是
如果(3x²-2)-(3x²-y)=-2,那么代数式(x+y)+3(x-y)-4(x-y-2)的值是

如果(3x²-2)-(3x²-y)=-2,那么代数式(x+y)+3(x-y)-4(x-y-2)的值是
(3x²-2)-(3x²-y)=-2
3x²-2-3x²+y=-2
y-2=-2
y=0
(x+y)+3(x-y)-4(x-y-2)
=x+y+3x-3y-4x+4y+8
=2y+8
=0+8
=8
很高兴为您解答,【the1900】团队为您答题.
请点击下面的【选为满意回答】按钮,

(3x²-2)-(3x²-y)=-2
3x²-2-3x²+y=-2
y=0
(x+y)+3(x-y)-4(x-y-2)
=x+y+3x-3y-4x+4y+8
=2y+8
=0+8
=8

将前式括号打开,3x^2被消掉了,可知y=0。那么将后式中括号打开,原式=x+y+3x-3y-4x+4y+8=2y+8=8
所以值为8