
How to solve part E). Not sure how to explain.
How to solve part E). Not sure how to explain.
Not exactly sure what the question wants either, especially since both solutions are equally valid. I would simply substitute the solutions as two separate scenarios to show that they are both valid.
Scenario 1: x = 70 | Mindy bought 70 books
Cost price per book: $168 ÷ 70 = $2.40
# of books left after selling 20 books: 70 – 20 = 50
Price which the remaining 50 books were sold: $2.40 – $2 = $0.40
Earnings from selling these 50 books: 50 x $0.40 = $20
Profit: ($240 + $20) – $168 = $92
Scenario 2: x = 24 | Mindy bought 24 books
Cost price per book: $168 ÷ 24 = $7
# of books left after selling 20 books: 24 – 20 = 4
Price which the remaining 4 books were sold: $7 – $2 = $5
Earnings from selling these 4 books = $20
Profit: ($240 + $20) – $168 = $92
Since both solutions are positive and real roots which satisfy the equation, both are equally valid in this context.