It means hold down the <CTRL> key while you hit the <9> key and let it up. It hides the row or rows that cells are selected in at that time.
Yes you can. Ctrl - 9 hides a row. Ctrl - 0 hides a column. Add the Shift key to those combinations and they can be unhidden.
Obviously, it closes the current window, you are in. I'm in Grade 9 BTW Well actually i think he should try it. Be a learning experience
=4+9
Click home tab, click hide and unhide, click unhide sheet. Click home tab, click hide and unhide click hide sheet.
Ctrl - 2009 Ctrl Y 1-9 was released on: USA: 25 August 2009
The sum of 27 occurrences of the number 9 is calculated by multiplying 27 by 9, resulting in 243.
If you mean: -1/9 plus -5/9 then it is equal to -6/9 which simplifies to -2/3
2 + 5 + 9 + 12 + 16 = 44/5 = 8.8
That is 27 x 9 = 243
189
-9
263