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

What is the number?

So let me give you the answer with procedure so that you can understand it better:

Let x = Number

Product of 9 and Number:

9x

is 12 less than 3 times that number. So:

3x - 12

Set them equal and solve for x like this:

9x = 3x - 12

6x = - 12

x = - 2

I hope this is very useful for you