Answer:
Population of bacteria at time
is 
Step-by-step explanation:
The complete question is
If
represents the number of bacteria in a culture at time t, how many will there be at time 
Solution
Given
The population of bacteria after time t is equal to 
Population when at time 
We will substitute the value of time in above equation.

Answer:
it shows commutative property
Answer:
2.4x105
Step-by-step explanation:
D
Answer:
$720
Step-by-step explanation:
$20000 - 100%
$x. - 2.5%
x=(20000*2.5)/100=500
20000+500=$20500 in one year (Mark)
20000 - 100
x. - 6.1
x= (20000*6.1)/100 = 1220
20000+1220= $21220 (Walter)
21220-20500= $720 more (Walter will have after 1 year)