Question

Salutare!
Daca stiti dumneavoastra, cum se rezolva, si sa-mi explicati ar fi perfect!
Multumesc anticipat

Answer 1

1.

a₂ = 4

Considerăm a₁ = 3, a₂ = 4, a₃ = 5

=> S = 3+4+5 = 12

2.

a₁ = a₃-6 => a₁ = a₁+2r-6 => 0 = 2r-6 =>

=> 2r = 6 => r = 3