Question

The product of 9 and a number is 12 less than three times that number.

Answer 1

9n = 3n-12
-3n= -3n   
6n= -12
 divide by 6 = -2 =n 

to check.. 9 times -2 = -18 soo.. 3 times -2= -6-12= -18 

so it is correct!! 
 
hope it helps :)