\[= 16 - 16 - 12 - 2a + b =\]
\[= - 2a + b - 12\]
\[P(1) =\]
\[= 1^{4} + 2 \bullet 1^{3} - 3 \bullet 1^{2} + a \bullet 1 + b =\]
\[= 1 + 2 - 3 + a + b = a + b\]
\[Ответ:\ при\ a = - 2\ и\ \ b = 8.\]