Question

if the sum of first 20 terms of arithmetic sequence is 1300 common difference 6.what is the algebraic from of the sequence ​

Answer 1

Step-by-step explanation:

according to formula,

1300=20/2{2a+(20-1).6}

1300=10(2a+114)

2a +114=130

2a=130-114=16

a=8

then the series is

8,14,20,26......

Answer 2

Answer:

Answer is , 8 , 14 , 20 ......

Step-by-step explanation:

Given :- S(20) = 1300 , common difference (d) = 6 , no. of terms (n) = 20

To find :- algebraic sequence .

Solution :-

Formula to used :- Sn = n/2 ( a + Tn )

                                     = n/2 ( a+a+(n-1)*d)

                                     =  n/2 (2*a + (n-1)*d)

Therefore ,  1300 = 20/2 ( 2*a+ (20-1)*6)

                    1300 = 10 (2a+114)

                    160 = 20a

Therefore ,  a = 8 .

thus the initial term is 8 .

hence the series goes as , 8 , (8+6) , (8+6+6) , .....

Answer is , 8 , 14 , 20 ......

#SPJ3