Step-by-step explanation:
The answer is B
Answers is B
Answer:
8t-3
(t-1)-(-7t+2)
t-1+7t-2
t+7t-1-2
8t-1-2
left
basta left XD
A
B
C
given
n=9
a=1
d=3-1=2
now , by formula,
sn = n/2(2a+(n-1)d)
= 9/2(2×1+(9-1)×2)
=9/2×18
=81