Answer:
A. y = 2.5(2)^x
Explanation:
Given that when
x = 1, f(x) = 5
x = 2, f(x) = 10
x = 3, f(x) = 20
x = 4, f(x) = 40
x = 5, f(x) = 80
x = 6, f(x) = 160
Considering all the options
y = 2.5(2)^x
Substitute x = 1
y = 2.5(2)^1 = 2.5 *2 = 5
Substitute x = 2
y = 2.5(2)^2 = 2.5 * 4 = 10
Substitute x = 3
y = 2.5(2)^3 = 2.5 * 8 = 20
Substitute x = 6
y = 2.5 (2)^6
= 2.5 * 64
= 160
Since the function is true for all the values of x substituted, then the answer is A. y = 2.5(2)^x