Because you are not adding the x's .When you add the coefficients, the variable comes along with it.
I got 5 times 45 because I multiplied by 5 to get my answer.
600kb in 24 seconds to find out how many kbs per second divide by 24
600/24 is 25kb
The original functions are: f(n) = 500 and g(n) = [9/10]^(n-1)
A geometric sequence combining them is: An = f(n)*g(n) = 500*[9/10]^(n-1):
Some terms are:
A1= 500
A2 = 500*[9/10]
A3 = 500*[9/10]^2
A4 = 500*[9/10]^3
....
A11 = 500*[9/10]^10 ≈ 174.339
Answer: the third option, An = 500[9/10]^(n-1); A11 = 174.339