The opposite of 12.1 is 12.2
Let p be the prize of a pen and m the prize of a mechanical pencils. If you buy six pens and one mechanical pencil, you spend 6p+m. We know that this equals 9, because you get 1$ change from a 10$ bill.
Similarly, if you buy four pens and two mechanical pencils, you spend 4p+2m, which is 8$, because now you get a $2 change. Put these equation together in a system:

Now, if you multiply the first equation by 2, the system becomes

Subtract the second equation from the first:

Plug this value into the first equation to get

Answer:
1536² mm
Step-by-step explanation:
16 x 16 = 256
256 x 6 = 1536 (6 = number of faces)
1536²mm
Answer 4
4multiplyed by 4 is 16
I think it would be JK but im not really sure