The square root of a number 2m-6 and 3M + 1, what is the number? How to write the process

The square root of a number 2m-6 and 3M + 1, what is the number? How to write the process

There are two square roots of a number, which are opposite to each other
So 2m-6 + 3M + 1 = 0
So m = 1
So this number = (3m + 1) &# = 16