1、(2x+3y)(3x-5y)-(x+y)(6x-7y)2、(2a-b+c)(b-c-2a)3、简便运算 99.8^24、简便运算 (10+1)(10^2+1)(10^4+1)(10^8+1)5\ 6(x+y)^2-2(x-y)(x+y)请勿灌水.
来源:学生作业帮助网 编辑:作业帮 时间:2024/09/06 14:19:26
![1、(2x+3y)(3x-5y)-(x+y)(6x-7y)2、(2a-b+c)(b-c-2a)3、简便运算 99.8^24、简便运算 (10+1)(10^2+1)(10^4+1)(10^8+1)5\ 6(x+y)^2-2(x-y)(x+y)请勿灌水.](/uploads/image/z/12258561-57-1.jpg?t=1%E3%80%81%EF%BC%882x%2B3y%EF%BC%89%EF%BC%883x-5y%EF%BC%89-%EF%BC%88x%2By%EF%BC%89%EF%BC%886x-7y%EF%BC%892%E3%80%81%EF%BC%882a-b%2Bc%EF%BC%89%EF%BC%88b-c-2a%EF%BC%893%E3%80%81%E7%AE%80%E4%BE%BF%E8%BF%90%E7%AE%97+99.8%5E24%E3%80%81%E7%AE%80%E4%BE%BF%E8%BF%90%E7%AE%97+%EF%BC%8810%2B1%EF%BC%89%EF%BC%8810%5E2%2B1%EF%BC%89%EF%BC%8810%5E4%2B1%EF%BC%89%EF%BC%8810%5E8%2B1%EF%BC%895%5C+6%28x%2By%29%5E2-2%28x-y%29%28x%2By%29%E8%AF%B7%E5%8B%BF%E7%81%8C%E6%B0%B4.)
1、(2x+3y)(3x-5y)-(x+y)(6x-7y)2、(2a-b+c)(b-c-2a)3、简便运算 99.8^24、简便运算 (10+1)(10^2+1)(10^4+1)(10^8+1)5\ 6(x+y)^2-2(x-y)(x+y)请勿灌水.
1、(2x+3y)(3x-5y)-(x+y)(6x-7y)
2、(2a-b+c)(b-c-2a)
3、简便运算 99.8^2
4、简便运算 (10+1)(10^2+1)(10^4+1)(10^8+1)
5\ 6(x+y)^2-2(x-y)(x+y)
请勿灌水.
1、(2x+3y)(3x-5y)-(x+y)(6x-7y)2、(2a-b+c)(b-c-2a)3、简便运算 99.8^24、简便运算 (10+1)(10^2+1)(10^4+1)(10^8+1)5\ 6(x+y)^2-2(x-y)(x+y)请勿灌水.
1.(2*3-1*6)x^2+(-5*2+3*3+1*7-1*6)xy-(3*5-1*7)y^2=-8y^2
2.(2a-b+c)(b-c-2a)=(2a-b+c)*-(2a-b+c)=-(2a-b+c)^2
3.99.8^2=(100-0.2)^2=100^2-2*100*0.2+0.2^2=10000-40+0.04=9960.04
4.11 101 (10^4+1)=10^2^2+1=100^2+1=10001
(10^8+1)=10^2^2^2+1=100^2^2+1=10000^2+1=100000001
5.6(x+y)^2-2(x-y)(x+y)=6(x+y)^2-2(x^2-y^2)
=6(x+y)^2-2x^2+^2y^2
=(6-2)x^2+(6*2)xy+(6+2)y^2
=4x^2+12xy+8y^2
=(2x+4y)(2x+2y)
(2*3-1*6)x^2+(-5*2+3*3+1*7-1*6)xy-(3*5-1*7)y^2=-8y^2
-(2a-b+c)(2a-b+c)=-(2a-b+c)^2
100^2+0.2^2-2*0.2=10000+0.04-0.4=999.64
(6+1)x^2+(6-1)y^2+12xy=7x^2+5y^2+12xy
2. (2a-b+c)(b-c-2a)
=(2a-b+c)[-(2a-b+c)]
=-(2a-b+c)^2
3. 99.8^2
=(100-0.2)^2
=100^2+0.2^2-2*100*0.2