Answer:
Its the first option
40,000,000(0.9)x.
Step-by-step explanation:
90% recognise her each year so after 1 year so the number (N) is:
N = 40,000,000(0.90)^1 = 36,000,000 recognise her after 1 year.
N = 40,000,000(0.90)^2 = 32,400,000 recognise her after 2 yeas
- and so on.
After x years:
N = 40,000,000(0.90)^x.
Note the x is a power and is best written as ^x.