Answer :
Answer:
Step-by-step explanation:
a1 = 5
common difference = 2nd term - 1st term= 14 -5 = 9
n = 31
[tex]S_{n}=\frac{n}{2}[2a+(n-1)d]\\\\S_{31}=\frac{31}{2}[2*5+30*9]\\\\=\frac{31}{2}[10+270]\\\\=\frac{31}{2}*280\\\\=31*140\\\\=4340[/tex]
Answer:
Step-by-step explanation:
a1 = 5
common difference = 2nd term - 1st term= 14 -5 = 9
n = 31
[tex]S_{n}=\frac{n}{2}[2a+(n-1)d]\\\\S_{31}=\frac{31}{2}[2*5+30*9]\\\\=\frac{31}{2}[10+270]\\\\=\frac{31}{2}*280\\\\=31*140\\\\=4340[/tex]