Question

What is the sum of the first 19 terms of an arithmetic series with a rate of increase of 7 and a7 = 46?
A)1,197
B)1,273
C)1,373
D)1,423
E)1,327

Answer 1

sum of n numbers Sn = n/2[2a + (n – 1)d]
a7= a + 6d
a + 6 × 7 = 46
a = 46 – 42 = 4

a is first term = 4
d = common difference = 7
n = total numbers = 19
S10 = 19/2[8 + 18 × 7
= 19/2[114
= 1273 --------- B

Answer 2

THANKS FOR THE MEDAL

Answer 3

no thank you <3

Answer 4

Jk

Answer 5

lol