Respuesta :
Answer:
Sum of arithmetic series is [tex]2077[/tex]
Step-by-step explanation:
We have [tex]n[/tex]th term of arithmetic sequence
[tex]a+(n-1)d[/tex]
Here
[tex]a+(n-1)d=127\\\\7+(31-1)d=127\\\\d=\frac{120}{30} \\\\=4[/tex]
Sum of arithmetic sequence [tex]=\frac{n}{2} (2a+(n-1)d)[/tex]
[tex]=\frac{31}{2} (2\times7+(31-1)4)\\\\=\frac{31}{2} (14+120)\\\\=31\times67\\\\=2077[/tex]
Answer:
The sum of arithmetic series is 2077.
Step-by-step explanation:
Solution :
Here we have provided that :
- »» [tex]\rm{a_1}[/tex] = 1
- »» [tex]\rm{n}[/tex] = 31
- »» [tex]\rm{a_n}[/tex] = 127
We need to find :
- »» The sum of arithmetic series.
Here's the required formula to find the sum of arithmetic series :
[tex]\longrightarrow{\pmb{\sf S = \dfrac{n}{2} \Big(a_1 + a_n \Big)}}[/tex]
Substituting all the given values in the formula to find the sum of arithmetic series :
[tex]{\longrightarrow{\sf S = \dfrac{n}{2} \Big(a_1 + a_n \Big)}}[/tex]
[tex]{\longrightarrow{\sf S = \dfrac{31}{2} \Big(7 + 127 \Big)}}[/tex]
[tex]{\longrightarrow{\sf S = \dfrac{31}{2} \Big(134 \Big)}}[/tex]
[tex]{\longrightarrow{\sf S = \dfrac{31}{2} \times 134 }}[/tex]
[tex]{\longrightarrow{\sf S = \dfrac{31}{\cancel{2}} \times \cancel{134 }}}[/tex]
[tex]{\longrightarrow{\sf S = 31 \times 67}}[/tex]
[tex]{\longrightarrow{\sf S = 2077}}[/tex]
[tex]\star \: {\underline{\boxed{\sf{\red{S = 2077}}}}}[/tex]
Hence, the sum of arithmetic series is 2077.
[tex]\rule{300}{1.5}[/tex]