Answer:
A) [First try is correct for all U1 to U4]
Step-by-step explanation:
1. Trying each option
(let x = 1,2,3,4) since it goes from U1 to U4 (Geometric sequence)
A.) 10(-4/5)^x
10(-4/5)^1 = -8
10(-4/5)^2 = 6.4
10(-4/5)^3 = -5.12
10(-4/5)^4 = 4.096
D
if x= number of hours replace the x by 9
so you have 5×(1.50)^9+10=
5×(192.21)+10 = 202.21 so 202 will be nearest whole number