Decimals are great for when you are dealing with money and want to round up, and fractions are used when baking (such as need 1/4 or a half cup of something)
This is because it is crossing as the same over the x-axis. The reflection of C would be the same, just over the x axis, meaning the -4 would become 4. If it were over the y-axis, it would be (-8,-4). Hope this helps.