a₁ = 19 a₁₁ = - 6
a₁₁ = a₁ + 10d
10d = a₁₁ - a₁ = - 6 - 19 = - 25
d = - 25 : 10 = - 2,5
a₄₀ = a₁ + 39d = 19 + 39 * (- 2,5) = 19 - 97,5 = - 78,5
Copyright © 2024 SCHOLAR.TIPS - All rights reserved.
Answers & Comments
Verified answer
a₁ = 19 a₁₁ = - 6
a₁₁ = a₁ + 10d
10d = a₁₁ - a₁ = - 6 - 19 = - 25
d = - 25 : 10 = - 2,5
a₄₀ = a₁ + 39d = 19 + 39 * (- 2,5) = 19 - 97,5 = - 78,5