Readers have a vested interest in something if they benefit directly from keeping things as they are

That statement is true

Vested interest only arise from personal desire without any intention of helping others. Some examples for vested interest would be when someone who work long hours to obtain a financial gain or someone who train boxing everyday in order to protect himself.

the first one you have to divide thenn add then multiply then add but mabey pemdaz pie equals 3.14 duuuhhh