Это арифметические прогрессии.
а) х1= 4 * 1 + 2 = 6; х2 = 4 * 2 + 2 = 10; d = 10 - 6 = 4
S50=(2 * 6 + 4 * 49)/2 * 50 = (12 + 196) /2 *50= 5200
2) x1 = 2 * 1 + 3 = 5; x2 = 2 * 2 + 3 = 7; d = 7 - 5 = 2
S50 = ( 2 * 5 + 2 * 49)/2 *50 = (10 + 98)/2 *50=2700
Copyright © 2025 SCHOLAR.TIPS - All rights reserved.
Answers & Comments
Это арифметические прогрессии.
а) х1= 4 * 1 + 2 = 6; х2 = 4 * 2 + 2 = 10; d = 10 - 6 = 4
S50=(2 * 6 + 4 * 49)/2 * 50 = (12 + 196) /2 *50= 5200
2) x1 = 2 * 1 + 3 = 5; x2 = 2 * 2 + 3 = 7; d = 7 - 5 = 2
S50 = ( 2 * 5 + 2 * 49)/2 *50 = (10 + 98)/2 *50=2700