In order to calculate the number of loaves Roger can bake, we should calcculate how many times 3/4 (required butter for one loaf of bread) is included in 2 1/2 (amount of butter Roger has).
2 1/2=4/2+1/2=5/2
(5/2)/(3/4)=5*4/2*3=20/6=3,33
Roger can bake 3 loaves of bread.
I think #7 is 40
#9 is 300
2x ! the number would be x and 2x is 2 times x!
