a1+a1+8d+a1+10d+a1+18d=4a1+36d
a1+2d+a1+16d=2a1+18d=21
4a1+36d=2(2a1+18d)=2*21=42
Copyright © 2024 SCHOLAR.TIPS - All rights reserved.
Answers & Comments
a1+a1+8d+a1+10d+a1+18d=4a1+36d
a1+2d+a1+16d=2a1+18d=21
4a1+36d=2(2a1+18d)=2*21=42