Ответ:
483.
Решение:
(аn): −12; −9; −6...
1) a1 = - 12.
2) d = a2 - a1 = - 9 - (- 12) = - 9 + 12 = 3.
3) S 23 = (2a1 + 22d)/2 • 23 = (2•(-12) +22•3)/2 • 23 = (-24+66)/2 • 23 = 42/2 • 23 = 21•23 = 483
Copyright © 2025 SCHOLAR.TIPS - All rights reserved.
Answers & Comments
Ответ:
483.
Решение:
(аn): −12; −9; −6...
1) a1 = - 12.
2) d = a2 - a1 = - 9 - (- 12) = - 9 + 12 = 3.
3) S 23 = (2a1 + 22d)/2 • 23 = (2•(-12) +22•3)/2 • 23 = (-24+66)/2 • 23 = 42/2 • 23 = 21•23 = 483