Question

а.п. -4;2;0 найти:S10​

Answer 1

а₁=-4

а₂=2

а₃=0

d=а₂-а₁=а₃-а₂=2

а₁₀=а₁+9d=-4+9·2=22

S₁₀=(1/2)(a₁+а₁₀)·10=5·(2+22)=120