I think it’s A hope this helped
Answer:
90
Step-by-step explanation:
To find s4 we find sum of values when n=1,n=2,n=3,n=4
given expression is 
n=1 , plug in 1 for n

n=2

n=3

n=4

Sum of all 4 terms = 6+12+24+48=90
1,000,000 is written as 10^6. Other wise it would be too low or too high.
Answer:
1 and 2
Step-by-step explanation:
gcd = 6 ⋅ d
Step-by-step explanation:
We have that
6
d
^2 = 6 ⋅ d ⋅ d and 18
d = 3 ⋅ 6 ⋅ d hence the gcd = 6 ⋅ d
(Hope this helps <3)