单复句子互换This is my brother This is his cousinThese 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
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单复句子互换This is my brother This is his cousinThese 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
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?
单复句子互换This is my brother This is his cousinThese 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
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