9m + 6 would be the answer
Better deal normlly means the rate that cost less
rate=cost/amount
9=cost and 3/4 bushel = amount for one store
3/4=0.75
9/0.75=12/1 aka $12/1bushel
9 =cost and 2/3 bushel =amount for another
2/3=about 0.66666
9/0.66666=13.5/1 aka $13.5/1 bushell
compare
12 dollars per bushe vs 13.5 dollar per bushel
12 is cheaper
therefor $9 For 3/4 bushel is better deal
The legnth is irrelivant
we know that
Circumference=2 times pi time radius
c=40
40=2 times pi times radius
divide both sides by 2
20=pi times radius
divide both sides b pi
20/pi=radius
the radius is 20/pi cm or aproximately 6.366199048 cm