Question

suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. write an equation that represents this situation.
y=5000x^x
y=5000(0.7)^x
y=5000(1.3)^x
y=30(5000)^x

Explanation:

Step1: Identify decay formula

Exponential decay formula: $y = a(1-r)^x$, where $a$ = initial amount, $r$ = decay rate, $x$ = time.

Step2: Plug in given values

$a=5000$, $r=0.30$, so $1-r=0.70$.
Expression: $y = 5000(0.7)^x$

Answer:

B. $y=5000(0.7)^x$