\[1)\ y = e^{\frac{1}{x - 1}};\]
\[y^{'}(x) = - 1 \bullet (x - 1)^{- 2} \bullet e^{\frac{1}{x - 1}} =\]
\[= - \frac{e^{\frac{1}{x - 1}}}{(x - 1)^{2}}.\]
\[2)\ y = \ln\left( 3 - 4x^{2} \right);\]
\[y^{'}(x) = - 4 \bullet 2x \bullet \frac{1}{3 - 4x^{2}} =\]
\[= \frac{8x}{4x^{2} - 3}.\]
\[3)\ y = e^{\frac{2}{x + 1}};\]
\[y^{'}(x) = 2 \bullet ( - 1) \bullet (x + 1)^{- 2} \bullet e^{\frac{2}{x + 1}} =\]
\[= - \frac{2e^{\frac{2}{x + 1}}}{(x + 1)^{2}}.\]
\[4)\ y = e^{\frac{1}{2x + 3}};\]
\[y^{'}(x) = 2 \bullet ( - 1) \bullet (2x + 3)^{- 2} \bullet e^{\frac{1}{2x + 3}} =\]
\[= - \frac{2e^{\frac{1}{2x + 3}}}{(2x + 3)^{2}}.\]
\[5)\ y = \ln\frac{2}{3 - 4x^{2}};\]
\[= \frac{8x}{3 - 4x^{2}}.\]
\[6)\ y = \ln\frac{3}{2x^{2} + 7x};\]
\[= - \frac{4x + 7}{2x^{2} + 7x}.\]