1.4 Lösning 9a
Från Mathonline
\( \left({1 \over 2\,x - 1} + {1 \over 2\,x + 1}\right) \cdot {2\,x + 1 \over 2\,x} = {2\,x + 1 \over 2\,x\,(2\,x - 1)} + {1 \over 2\,x} = \)
\( = {2\,x + 1 \over 2\,x\,(2\,x - 1)} + {2\,x - 1 \over 2\,x\,(2\,x - 1)} = {2\,x + 1 + 2\,x - 1 \over 2\,x\,(2\,x - 1)} = \)
\( = {4\,x \over 2\,x\,(2\,x - 1)} = {2 \over 2\,x - 1} \)
