1/1x2+1/2x3+1/3x4+1/4x5+……1/8x9+1/9x10=?(简便算法)快~~~~~
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/29 01:46:47
![1/1x2+1/2x3+1/3x4+1/4x5+……1/8x9+1/9x10=?(简便算法)快~~~~~](/uploads/image/z/1025905-49-5.jpg?t=1%2F1x2%2B1%2F2x3%2B1%2F3x4%2B1%2F4x5%2B%E2%80%A6%E2%80%A61%2F8x9%2B1%2F9x10%3D%3F%28%E7%AE%80%E4%BE%BF%E7%AE%97%E6%B3%95%EF%BC%89%E5%BF%AB%7E%7E%7E%7E%7E)
1/1x2+1/2x3+1/3x4+1/4x5+……1/8x9+1/9x10=?(简便算法)快~~~~~
1/1x2+1/2x3+1/3x4+1/4x5+……1/8x9+1/9x10=?(简便算法)
快~~~~~
1/1x2+1/2x3+1/3x4+1/4x5+……1/8x9+1/9x10=?(简便算法)快~~~~~
1/1x2+1/2x3+1/3x4+1/4x5+……1/8x9+1/9x10
=1-1/2+1/2-1/3+1/3-1/4+.+1/8-1/9+1/9-1/10
=1-1/10
=9/10
1/1x2=1/1-1/2
1/2x3=1/2-1/3
...
1/9x10=1/9-1/10
1/1x2+1/2x3+1/3x4+1/4x5+……1/8x9+1/9x10=1-1/10=9/10
1/1x2+1/2x3+1/3x4+1/4x5+……1/8x9+1/9x10
=1-1/2+1/2-1/3+1/3-1/4+……+1/9-1/10
中间全部抵消
=1-1/10
=9/10
公式:1/m*n=1/m-1/n
嘿嘿嘿全民漂移祝你学习进步!
裂项相消。
公式应是1/m*n=(1/m-1/n)*(n-m)
因式分解:x4+x3+2x2 +x+1
用克拉默法则解下列方程组 x1-2x2+3x3-4x4=4 x2-x3+x4=-3 x1+3x2+2x4=1 -7x2+3x3+x4=3x1-2x2+3x3-4x4=4x2-x3+x4=-3 x1+3x2+2x4=1 -7x2+3x3+x4=3
解方程组X1-2x2+3x3-x4=1,3x1-x2+5x3-3x4=2,2x1+x2+2x3-2x4=3
x1+5x2-x3-x4=-1x1-2x2+x3+3x4=33x1+8x2-x3+x4=1
写出方程组2*x1+x2-x3+x4=1,x1+2*x2+x3-x4=2,x1+x2+2*x3+x4=3的通解?
求非齐次线方程组的通解 :2x1+x2-x3+x4=1 x1+2x2+x3-x4=2 x1+x2+2x3+x4=3
具体写出方程组:2x1+x2-x3+x4=1;x1+2x2+x3-x4=2;x1+x2+2x3+x4=3的通解
解一道方程组x1+x2+x3=5,x2+x3+x4=1,x3+x4+x5=-5,x4+x5+x1=-3,x5+x1+x2=2
用初等行变换来解下列线性方程组(1)2x1-x2+3x3=3 3x1+x2-5x3=0 4x1-x2+x3=3 x1+3x2-13x3=-6(2) x1-2x2+x3+x4=1 x1-2x2+x3-x4=-1 x1-2x2+x3-5x4=5(3) x1-x2+x3-x4=1 x1-x2-x3+x4=0 x1-x2-2x3+2x4=-1/2
1X2+2X3+3X4+.NX(N+1)
1X2+2X3+3X4+.NX(N+1)规律
1x2+2x3+3x4+.+2011x2012
1x2+2x3+3x4+4x5+.+15x16
1x2+2x3+3x4+.+100x101=
1x2+2x3+3x4+.+100x101=?结果
1x1!+2x2!+3x3!+4x4!.nxn!
1X2+2x3+3x4+……+2013x2014
1x2+2x3+3x4+.+19x20