Verified Answer :

25 - 7 = 18
18 + 12 = 30 books Ava has now

Solve:-

25 books in total
gives 7 books
gets 12 books

Subtract and then add:-

25 - 7 = 18 books after giving 7 away
18 + 12 = 30 after getting 12 more

Ava has 30 books now.