Answer:
$5800
Explanation:
The income that would be earned if the summer courses were not taken is $5000 while we spend only $100 on food.
Besides, by taking the summer courses costs to be incurred is computed thus:
costs of summer courses=$1,200+$400+$300=$1900
By taking the summer courses one would earn $1000
In short, the opportunity of taking the summer courses is the earnings of -$5000 forgone plus the cost of $100 saved, plus the $1000 earned minus the $1900 spent on summer courses
i.e -$5000+$100+$1000-$1900=-$5800