[tex]\displaystyle\bf\\a_{1} =5\\\\a_{2} =7\\\\a_{21}=?\\\\\\a_{2} =a_{1} +d\\\\d=a_{2} - a_{1} =7-5=2\\\\\\a_{21} =a_{1} +20d=5+20\cdot 2=5+40=45\\\\\\Otvet \ : \ a_{21} =45[/tex]
Copyright © 2024 SCHOLAR.TIPS - All rights reserved.
Answers & Comments
Verified answer
[tex]\displaystyle\bf\\a_{1} =5\\\\a_{2} =7\\\\a_{21}=?\\\\\\a_{2} =a_{1} +d\\\\d=a_{2} - a_{1} =7-5=2\\\\\\a_{21} =a_{1} +20d=5+20\cdot 2=5+40=45\\\\\\Otvet \ : \ a_{21} =45[/tex]