The task is to generate the correct answer for a given math problem.
--------
Question: Problem: solve the equation for x : 6 x - 47 + 3 x = 4 + 9 - x

Answer:

Question: Problem: if a * b * c = ( ( a + 2 ) ( b + 3 ) ) / ( c + 1 ) , find the value of 6 * 15 * 1 .

Answer: 2

Question: Problem: in a certain alphabet , 9 letters contain a dot and a straight line . 24 letters contain a straight line but do not contain a dot . if that alphabet has 40 letters , all of which contain either a dot or a straight line or both , how many letters contain a dot but do not contain a straight line ?

Answer:
7