Answer:
[tex]A=400\ people[/tex]
Step-by-step explanation:
we have
[tex]Q=600+\sqrt{A+41}[/tex]
where
Q -----> is the daily output
A -----> is the number of people
For Q=621
Find the value of A
substitute and solve for A
[tex]621=600+\sqrt{A+41}[/tex]
Subtract 600 both sides
[tex]621-600=\sqrt{A+41}[/tex]
[tex]21=\sqrt{A+41}[/tex]
squared both sides
[tex]21^{2} ={A+41}[/tex]
[tex]441={A+41}[/tex]
Subtract 41 both sides
[tex]441-41=A[/tex]
Rewrite
[tex]A=400\ people[/tex]