Copy the note from Google Keep (Highlight the note, hit Ctrl + C) then open a new doc and hit Ctrl + V. There you go, if this answer was not of use, please elaborate on your question so I can fix any mistakes.
The answer is -15. This because 12 * 15 = 180 so in order to make it negative one of the integers has to be negative and since 12 is given you have to make 15 negative.
