This image shows some kind of formula that could be converted to TeX. Storing formulas as images makes it harder to change them. TeX also helps making sure that they all use the same font and size. A replacement has been proposed:
DescriptionThe commutative property of addition.png
English: For any numbers, a and b, a plus b is equal to b plus a. From this we know that addition is commutative, meaning that the operation of addition can be performed in any order with the same result.
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.