1 |
4 |
設(shè)
1 |
4 |
則
1 |
4 |
3 |
4 |
故等差數(shù)列的公差d=(
3 |
4 |
1 |
4 |
1 |
6 |
則x2=
5 |
12 |
7 |
12 |
∴a=
1 |
4 |
3 |
4 |
3 |
16 |
5 |
12 |
7 |
12 |
35 |
144 |
故a+b=
3 |
16 |
35 |
144 |
62 |
144 |
31 |
72 |
故選A
1 |
4 |
31 |
72 |
13 |
24 |
11 |
24 |
3 |
8 |
1 |
4 |
1 |
4 |
1 |
4 |
3 |
4 |
3 |
4 |
1 |
4 |
1 |
6 |
5 |
12 |
7 |
12 |
1 |
4 |
3 |
4 |
3 |
16 |
5 |
12 |
7 |
12 |
35 |
144 |
3 |
16 |
35 |
144 |
62 |
144 |
31 |
72 |