Inequality, because want to know when we'll make a profit.
[tex]d (- 680+ 960) \geqslant 52000 \\ 280d \geqslant 52000[/tex]
Profit: Let's See When 280d equals 52000
[tex]d \geqslant \frac{52000}{280} \\ d \geqslant 185.71[/tex]
So, after 190 days Julianne will make a profit
[tex]280(190) \geqslant 52000 \\ 53200[/tex]
