10^13 cause you add the exponents together
You do 9x27=243 then take 2x31=62 add 243+62=305 then take 305 and subtract it from 28 305-28=277
so if i did it right you should get n=277
+2
-8-(-10
You can just add a plus in the middle
-8+(10=+2
This is definitely 12 the answer is 12 LOL