A negative exponent shows that the decimal point is shifted that number of places to the left. On other hand in the image A B C the letters ABC are arranged in counter clockwise order. In the orignal shape preimage the order of the letters is ABC going clockwise.
You should expect math notation to be hard because it packs a lot of meaning into very few symbols so you have to slow down and take it one equation at a time without any skimming.
Count the number of times that you moved the decimal. You always increase by one at each successive step. Displaystylesum_ n14 dfrac k n1 n14. You should expect math notation to be hard because it packs a lot of meaning into very few symbols so you have to slow down and take it one equation at a time without any skimming.