Answer:
[tex]\sum -5-9-13-17-21[/tex] =-65
Step-by-step explanation:
given nos -5,-9,-13,-17,-21
common difference=-4
given series are in arithmetic progression,
[tex]\sum -5-9-13-17-21[/tex]=[tex]n\div 2\left \{ a+l \right \}[/tex]
where, n=5 , a=first term=-5 , l=last term=-21
[tex]\sum -5-9-13-17-21[/tex]=[tex]5\div 2\left \{ -5-21\right \}[/tex]
[tex]\sum -5-9-13-17-21[/tex] =[tex]5\div 2\left \{ -26\right \}[/tex]
[tex]\sum -5-9-13-17-21[/tex] =-65 answer
