sn为等差数列an的前n项和若3s3=s2+s4

2025-02-16

sn为等差数列an的前n项和,s2=s6

2025-02-16

sn为等差数列an的前n项和,且a1=1,s7=28

2025-02-16

若sn/n为等差数列

2025-02-16

sn为等差数列an的前n项和,已知a7=1

2025-02-16

sn为等差数列an的前n项和,s4=0.a5=5

2025-02-16

sn为等差数列an的前n项和,s9=-a5

2025-02-16

若sn为等比数列前n项和,则sn,s2n

2025-02-16

sn是等差数列an的前n项和,若s3/s6=1/3

2025-02-16

sn为等差数列an的前n项和,已知an>0

2025-02-16

sn为等差数列an的前n项和若3s3=s2+s4

2025-02-16

sn为等差数列an的前n项和,s2=s6

2025-02-16

sn为等差数列an的前n项和,且a1=1,s7=28

2025-02-16

若sn/n为等差数列

2025-02-16

sn为等差数列an的前n项和,已知a7=1

2025-02-16

sn为等差数列an的前n项和,s4=0.a5=5

2025-02-16

sn为等差数列an的前n项和,s9=-a5

2025-02-16

若sn为等比数列前n项和,则sn,s2n

2025-02-16

sn是等差数列an的前n项和,若s3/s6=1/3

2025-02-16

sn为等差数列an的前n项和,已知an>0

2025-02-16