Answer:
7 fishes
Step-by-step explanation:
Given the growth of the population of fish which is modeled by the exponential function:
[tex]P(t)=7 \cdot b^t[/tex]
Where:
t=time in weeks after release
b=growth rate of the fish
At t=0
[tex]P(0)=7 \cdot b^0\\P_0=7 \cdot 1 \\P_0=7[/tex]
The initial number, [tex]P_0[/tex] of fish which was released into the lake is 7.