Respuesta :

ab-ac=a(b-c)
a is common factor
find common factor
factor the numbers

24=2*2*2*3
18y=2*3*3*y

common factor is 2*3 or 6

6(4)-6(3y)=6(4-3y)
In order to factor this expression, you must find the greatest common factor between 24 and 18. This number is 6. 
6(4-3y)
Extracting 6 will give you the expression above. There is no way to factor further, so this is the answer.
To check and see if you are right, distribute the 6 and you will get the original expression (24-18y).