Answer-
The equation is [tex]960d-650d = 52000[/tex] and Julianne will begin making a profit after 168 days.
Solution-
Julianne's start-up cost = $52,000,
Each day, she spends = $650,
and she earns = $960 per day,
If 'd' is the number of days to overcome the start-up and daily operation cost, then
total operation cost of d days = $650d and
total student lesson fees earned in d days = $960d
∴ The equation to represent the situation is,
[tex]960d-650d = 52000[/tex]
∴ Julianne will begin making a profit,
[tex]\Rightarrow 960d-650d \geq 52000[/tex]
[tex]\Rightarrow 310d \geq 52000[/tex]
[tex]\Rightarrow d \geq \frac{52000}{310} =167.74 \approx168(ans)[/tex]