\[\left( x^{\backslash 1 + x} + \frac{6 - x^{2}}{1 + x} \right)\ :\frac{6 + x}{x^{2} - 1} =\]
\[= \frac{(x + 6)(x - 1)(x + 1)}{(1 + x)(6 + x)} = x - 1\]