think the 4 less than but not equal to as a equal sign
step 1. isolate the variable ( variable must stand alone)
step 2. subtract 12n -12n=0
step 3. since you subtract 12n from the left you must do the same to the right.
step 4. 13n - 12n =1n
step 5. the equation should look like this -4 less than but not equal to 1n
step 6. isolate the variable n
step 6. divide 1n/1 on the right and on the left -4/1 it equals -4
so, n is -4