Why do we want cryptographic hash functions in Bitcoin?
Or any blockchain system for that matter?

We want blockchain systems in bitcoin because it is protecting your information using codes. Specifically, the information is assimilated in blocks using cryptographic technologies and it is added to the next block as a representative of the information in the previous block.

x=3

step-by-step explanation:

this is really simple i saw that there was only one term (5x) and thought if that was 15 what would i have to multiply everything else to get it there? well if 5x became 15 then x would have to be 3 so plug the 3 in the x for the other equations and you get 15 for the other ones. so there you go. : )