You close a question with a question mark..right?
Answer:
<em>Zeina had 35 books and Ali had 5 books</em>
Step-by-step explanation:
<u>Equations</u>
We know Zeina has seven times as many books as Ali. If we call
x = Number of books Ali has
Then Zeina has
7x = Number of books Zeina has
We also know if Zeina gave Ali 15 books, they would have the same number of books, thus:
x + 15 = 7x - 15
Adding 15:
x + 15 +15 = 7x
Subtracting x:
15 +15 = 7x - x
Operating:
30 = 6x
Dividing by 6:
x = 30 / 6
x =5
7x = 35
Thus Zeina had 35 books and Ali had 5 books
F(x) is basically the output or y of whatever x is