Three consecutive integers are n, n + 1, and n + 2. Four time s the sun of the least and greatest integers is 12 less than three times the least integer. What is the least integer? (Answer is - 4 but I need to know how to do it)

4 times the sum of the least and greatest integers ⇒ 4 (n + n + 2) = 4n + 8

12 less than three times the least integer ⇒ 3n - 12

4n + 8 = 3n - 12

4n - 3n + 8 = 3n - 3n - 12

n + 8 - 8 = - 12 - 8

n = - 20

-20, - 19, - 18 are the integers and the least is - 20