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
Six and eighty hundred thirty seven thousandths
Answer:
the answer is -7
Step-by-step explanation:
hope this helps
1. Supplementary
2. Complementary
3. Adjacent angles
4. Vertically opposite angles
Hope it helps. Please mark brainliest.