Answer:
14 books
Step-by-step explanation:
Let b = number of books at the beginning
She sold 1/2 of the books
b - 1/2 b
This is how many she had left
Then she bought 7
b - 1/2 b + 7
this equals 14
b - 1/2 b + 7 = 14
Combine like terms
1/2 b + 7 = 14
Subtract 7 from each side
1/2 b = 14-7
1/2 b = 7
Multiply each side by 2
1/2 b * 2 = 7*2
b = 14
She started with 14 books
