Question

代数·拜托了·急需呀

1. a,-1/3a+3/5a²与-1/2a²的和

2. x²y-2³xy²,3²x²y与-2²x²y+7xy²的和

3. （x²-2y²-3z²）-（-y²+3x²-z²）+（5x²+2y²）

4. 4x-2（x-1）-3[x-7（x-2）+1]

5. 比-x²+x-5大x²-3x+1的多项式

6. 多项式5xy-4x²与2y²-3xy的和，减去多项式-7x²+xy+4y²的差

7. 3a²b，-ab²-3a²b与2ab²-a²b的和

8. 1/2a-(a+2/3b²）+3（-1/2a+1/3b²）

9. -（p+q）-[2p-q-(3q-p)]

10. -3(2x²+3x+5)-5(2/5x²-6/5x-1)+3(-2x²+x+1)

11. 求整式0.16x²y-3.2x减去整式2.7y²-0.16x²y-1.2xy的差与整式0.12x²y+2.7y²的和

12. 整式5x³y+2x²y-x+4减去整式8x³y-7xy²

Answer 1

1. a,-1/3a+3/5a²与-1/2a²的和
=a-1/3a+3/5a^2-1/2a^2
=2/3a+1/10a^2
2. x²y-2³xy²,3²x²y与-2²x²y+7xy²的和
=x^2y-8xy^2+9x^2y-4x^2y+7xy^2
=6x^2y-xy^2
3. （x²-2y²-3z²）-（-y²+3x²-z²）+（5x²+2y²）
=x^2-2y^2-3z^2+y^2-2x^2+z^2+5x^2+2y^2
=4x^2+y^2-2z^2
4. 4x-2（x-1）-3[x-7（x-2）+1]
=4x-2x+2-3x+21x-45
=20x-43
5. 比-x²+x-5大x²-3x+1的多项式
=-x^2+x+x^2-3x+1
=1-2x
6. 多项式5xy-4x²与2y²-3xy的和，减去多项式-7x²+xy+4y²的差
=5xy-4x^2+2y^2-3xy+7x^2-xy-4y^2
=2xy+3x^2-2y^2
7. 3a²b，-ab²-3a²b与2ab²-a²b的和
=3a^2b-ab^2-3a^2b-2ab^2-a^2b
=-a^2b-3ab^2
8. 1/2a-(a+2/3b²）+3（-1/2a+1/3b²）
=1/2a-a-2/3b^2-3/2a+ b^2
=-2a+1/3b^2
9. -（p+q）-[2p-q-(3q-p)]
=-p-q-2p+q+3q-p
=3q-4p
10. -3(2x²+3x+5)-5(2/5x²-6/5x-1)+3(-2x²+x+1)
=-6x^2-9x-15-2x^2+6x+5-6x^2+3x+3
=-14x^2-7
11. 求整式0.16x²y-3.2x减去整式2.7y²-0.16x²y-1.2xy的差与整式0.12x²y+2.7y²的和
=0.16x²y-3.2x-2.7y²+0.16x²y+1.2xy+0.12x²y+2.7y²
=0.44x^2y-3.2x+1.2xy
12. 整式5x³y+2x²y-x+4减去整式8x³y-7xy²
=5x³y+2x²y-x+4-8x³y+7xy²
=-3x^3y+2x^2y+7xy^2+4

Answer 2

这么简单的数学题都要漫天下找答案，有点不好吧。好好把基础知识学习一下，吧代数书上基本定义、定理、公式理解并熟悉掌握，这些题都不难了。