Ответ:

  1. \(y-27=45\)
    \(y=45+27=72\).
  2. \(37+x=64\)
    \(x=64-37=27\).
  3. \(63-(25+z)=26\)
    \(25+z=63-26=37\),
    \(z=37-25=12\).
  4. \((x-63)+308=41\)
    \(x-63=41-308=-267\),
    \(x=-267+63=-204\).

Ответ: \(y=72\), \(x=27\), \(z=12\), \(x=-204\).