а13=а11+2d⇒a11+a11+2d=122
2a11+2d=122
2(a11+d)=122
a11+d=122/2
a11+d=61
a11+d=a12=61
Copyright © 2025 SCHOLAR.TIPS - All rights reserved.
Answers & Comments
а13=а11+2d⇒a11+a11+2d=122
2a11+2d=122
2(a11+d)=122
a11+d=122/2
a11+d=61
a11+d=a12=61