Rules how to subtract fractions Videos

Really helpful thanks\\\\\\\\\\\\\\\\:)

Please accept my apologies. I prewrote each card before recording the lecture while at the same time we had imposed a time limit on the length of each lecture. As it sometimes happens I ran out of time before I had finished what was written on the last card. The unfinished part meant to illustrate that we could just have logically seen what would happen for the same amount of pens at each price. In other words, there are times when it is just as logical to find a common numerator as it is to find a common denominator. For example at a rate of 2 pens for 3 dollars, 6 pens would have cost 9 dollars; while at a rate of 3 pens for 7 dollars, 6 pens would have cost 14 dollars. So by buying 6 pens at a rate of 2 pens for 3 dollars rather than at a rate of 3 pens for 7 dollars, we save 5 dollars.