Ответ:

а) \(512-491.2=20.8\), \(1.53\cdot54=82.62\), \(0.42\cdot20.8=8.736\).

\(82.62-8.736+1.116=75\).

б) \(27.12+43.08=70.2\), \(70.2\cdot0.007=0.4914\).

\((0.4914-0.0314)\cdot100=0.46\cdot100=46\).

Ответ: а) 75; б) 46.