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
Answer: her monthly payments would be $267
Step-by-step explanation:
We would apply the periodic interest rate formula which is expressed as
P = a/[{(1+r)^n]-1}/{r(1+r)^n}]
Where
P represents the monthly payments.
a represents the amount of the loan
r represents the annual rate.
n represents number of monthly payments. Therefore
a = $12000
r = 0.12/12 = 0.01
n = 12 × 5 = 60
Therefore,
P = 12000/[{(1+0.01)^60]-1}/{0.01(1+0.01)^60}]
12000/[{(1.01)^60]-1}/{0.01(1.01)^60}]
P = 12000/{1.817 -1}/[0.01(1.817)]
P = 12000/(0.817/0.01817)
P = 12000/44.96
P = $267
Q = 3s - 9/6
q = 3(s - 3)/6
q = s - 3/2
6q + 9 = 3s
6q + 9/3 = s
3(2q + 3)/3 = s
2q + 3 = s
s = 2q + 3
