which equation models an exponential decay

y=1/4x500^x

1/3y=6x100^x

y=0.5x8^x

y=23x(1/2)^x

y=0.004x2^x

i think it is d

To determine which equation models an exponential decay, we need to understand the general form of an exponential decay equation.

Exponential decay equations have the form: y = a * b^x, where 'a' is a constant and 'b' is a base value between 0 and 1.

Let's analyze each equation to see if it matches the form of an exponential decay equation:

a) y = (1/4) * 500^x
This equation has the form of an exponential growth equation, where the base (500) is greater than 1. Therefore, it does not model exponential decay.

b) (1/3)y = 6 * 100^x
By multiplying both sides of the equation by 3, we get: y = 18 * 100^x.
This equation has the form of an exponential growth equation, where the base (100) is greater than 1. Therefore, it does not model exponential decay.

c) y = 0.5 * 8^x
This equation has the form of an exponential decay equation, where the base (8) is greater than 0 and less than 1. Therefore, it models exponential decay.

d) y = 23 * x * (1/2)^x
This equation has an additional linear factor of 'x' multiplied by the base (1/2)^x, which makes it a combination of linear and exponential decay. Therefore, it does not solely model exponential decay.

e) y = 0.004 * 2^x
This equation has the form of an exponential decay equation, where the base (2) is greater than 0 and less than 1. Therefore, it models exponential decay.

Based on our analysis, the equations that model exponential decay are: c) y = 0.5 * 8^x and e) y = 0.004 * 2^x. So, your answer is correct, equation d) does indeed model an exponential decay.