单复句子互换This is my brother This is his cousinThese are ID card

来源：学生作业帮编辑：搜搜做题作业网作业帮分类：数学作业时间：2024/06/06 00:27:19

单复句子互换
This is my brother
This is his cousin
These are ID card
Those are baseballs
Is yhis your faher?
X-[y-2x-(x-y)}
2(a²b-3ab²)-3(2a²b-7ab²)
一直m²与-2n²的和为A,1+n²与-2m²的差为B,求2A-4B
先化简再求值：4X²Y-{6xy-3（4xy-2）-x²y｝+1其中x=2,y=二分之一
由于看错了符号,某学生把一个多项式减去x²+6x-6误当成了加法计算,结果得到2x²-2x+3,正确的结果应该是多少?

我是个高中生,下面为你解答
These are my brothers
These are his cousins
This is ID card
That is baseball
Are these your fathers? 很简单的
下面是数学
X-[Y-2X-(X-Y)]=X-Y+2X+(X-Y)=X-Y+2X+X-Y=4X-2Y 注意式子钱为-要加变减减变加 +则不用照抄就行
2(a2b-3ab2)-3(2a2b-7ab2)=2a2b-6ab2-6a2b+21ab2=15ab2-4a2b=还可以把ab提出来=ab（15b-4a）
m2与-2n2的和为A ∴A=m2-2n2 1+n2与-2m2的差为B ∴ B=1+n2+2m2
2A-4B=2（m2-2n2）-4（1+n2+2m2）=-6m2-4n2-4
4X2Y-{6xy-3（4xy-2）-x2y｝+1=3x2y+6xy-5 又x=2 y=? ∴原式=6+6-5=7
最后一题设原来的多项式为A ∴A+x2+6x-6=2x2-2x+3 A=x2-8x+9
∴A-（x2+6x-6）=x2-8x+9-x2-6x+6=15-14x

单复句子互换This is my brother This is his cousinThese are ID card This is ID card. this is my ID card同义句 This is an ID card This is my ID card.变成一般疑问句 This is my (s )ID card.填什么 This is my an ID card number 改错 This is my s_____ ID card 填什么 is this _____ ID card?--- No,it's my ID card Look!Is this ID card?改正错误进Is this Cindy's ID card? This is an ID card还是This is a ID card