\[- 30;\ - 28;\ - 26;\ldots\]
\[a_{1} = - 30;\ \ a_{2} = - 28;\]
\[d = - 28 + 30 = 2;\ \]
\[a_{28} = a_{1} + 27d = - 30 + 27 \cdot 2 =\]
\[= - 30 + 54 = 24.\]
\[Ответ:a_{28} = 54.\]