You divide 48 by 7 and you get the remainder of 6.8 . Therefore he can ONLY put 6 books in each box.
12m²n² -8mn +1
[6mn-1]•[ 2mn-1]
[ 6mn•2mn + 6mn•-1 + -1•2mn +-1•-1]
= [ 12 m²n² -6mn -2mn +1]
= [ 12m²n2-8mn+1]
.........
First you would take one and move it over to the left side and never leave for why and then you divide by one which would leave for why and it would also have X equals 4Y and then you divide ask my Y and I will just leave you which is XY equals four
Do you need to show your work? the answer is 114.25