题目
题型:填空题难度:一般来源:贵港
1 |
1×2 |
1 |
1 |
1 |
2 |
1 |
2×3 |
1 |
2 |
1 |
3 |
1 |
3×4 |
1 |
3 |
1 |
4 |
2 |
1×2 |
2 |
2×3 |
2 |
3×4 |
2 |
n×(n+1) |
答案
1 |
2 |
1 |
2 |
1 |
3 |
1 |
3 |
1 |
4 |
1 |
n |
1 |
n+1 |
1 |
n+1 |
2n |
n+1 |
2n |
n+1 |
核心考点
试题【观察下列各等式:11×2=11-12,12×3=12-13,13×4=13-14,…根据你发现的规律,计算:21×2+22×3+23×4+…+2n×(n+1)=】;主要考察你对分式的加减运算等知识点的理解。[详细]
举一反三
2 |
x+3 |
2 |
3-x |
2x+18 |
x2-9 |
1 |
b |
1 |
c |
1 |
a |
1 |
c |
1 |
a |
1 |
b |
x-y |
x+y |
2x+1 |
(x-1)(x+2) |
A |
x-1 |
B |
x+2 |