Edit for proper grammar
Neither of the textbooks contain the answer to the test question.
Neither is the subject of this sentnece and is singular.
The verb should also be singular -- contains.
Neither contains . . .
The patient talked about his childhood on the psychiatrist’s couch.
Did the patient spend his childhood on the psychiatrist's couch?
To edit this sentence for proper grammar, you can make the following changes:
"Neither of the textbooks contains the answer to the test question."
Explanation:
1. Change "neither" to "neither of" to indicate that there are two textbooks being referred to.
2. Use "contains" instead of "contain" because "neither" is a singular subject.
3. Add a period at the end of the sentence to indicate its completion.