Abookstore costs $90 a day to keep open, and it spends $13 for each book-
that it sells. if each book sells for $16, what is the break-even point for this
bookstore?
α. n = 16
β. n= 30
c. n= 13
d. n= 3

n = 30

Step-by-step explanation:

since it cost 90 to keep open, the equation needs to equal 90

90 = ?

because it cost 13 for a book and x equals the amount of books

90 = -13x

because you make 16 for each book

90 = -13x + 16x

now you can simply

90 = 3x

x = 30

so the answer is 30

i think it would be 42cm

x² + 3x + 7 = 0       [ax² + bx + c]

a = 1

b = 3

c = 7

quadratic formula:

    (+/- is this ±)

plug in the numbers into the variables

your answer is a