\[\boxed{\text{215}\text{\ (215)}\text{.}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
Пояснение.
Решение.
\[\textbf{а)}\ x = - 7;\ \ x = 2:\ \]
\[(x + 7)(x - 2) = x^{2} - 2x + 7x -\]
\[- 14 = x^{2} + 5x - 14;\]
\[\textbf{б)}\ x = 3 - \sqrt{2};\ \ x = 3 + \sqrt{2}:\]
\[\left( x - \left( 3 - \sqrt{2} \right) \right)\left( x - \left( 3 + \sqrt{2} \right) \right) =\]
\[= \left( x - 3 + \sqrt{2} \right)\left( x - 3 - \sqrt{2} \right) =\]
\[= \left( (x - 3) + \sqrt{2} \right) \cdot\]
\[\cdot \left( (x - 3) - \sqrt{2} \right) =\]
\[= (x - 3)^{2} - \left( \sqrt{2} \right)^{2} =\]
\[= x^{2} - 6x + 9 - 2 = x^{2} - 6x + 7.\]