\[\boxed{\text{935.}\text{\ }еуроки - ответы\ на\ пятёрку}\]
\[\textbf{а)}\ x³ + 7x² + 8 +\]
\[+ \left( x^{2} - 6x + 4 \right)(x - 1) =\]
\[= x^{3} + 7x^{2} + 8 + x^{3} - 6x^{2} +\]
\[+ 4x - x^{2} + 6x - 4 =\]
\[= 2x^{3} + 10x + 4\]
\[\textbf{б)}\ \left( a^{2} + 7a - 4 \right)(a - 3) -\]
\[- \left( a^{3} + 4a^{2} - 29a + 11 \right) =\]
\[= a^{3} + 7a^{2} - 4a - 3a^{2} - 21a +\]
\[+ 12 - a^{3} - 4a^{2} + 29a - 11 =\]
\[= 4a + 1\]