[tex]v_{0} =\dfrac{v_{1} m_{1} +v_{2} m_{2} }{m_{1} +m_{2} } ~~zal.~~{m_{1} \neq -m_{2}[/tex]
[tex]v_{0} =\dfrac{v_{1} m_{1} +v_{2} m_{2} }{m_{1} +m_{2} }~~\mid \cdot ({m_{1} +m_{2} )\\\\\\[/tex]
[tex]v_{0} ({m_{1} +m_{2} ) =v_{1} m_{1} +v_{2} m_{2}[/tex]
[tex]v_{0} {m_{1} +v_{0}m_{2} =v_{1} m_{1} +v_{2} m_{2}[/tex]
[tex]v_{0} {m_{1} -v_{1} m_{1} =v_{2} m_{2}-v_{0}m_{2}[/tex]
[tex]{m_{1}(v_{0} -v_{1} ) =v_{2} m_{2}-v_{0}m_{2} ~~\mid \div (v_{0} -v_{1} )[/tex]
[tex]m_{1} =\dfrac{v_{2} m_{2}-v_{0}m_{2} }{v_{0} -v_{1}} ~~zal. ~~v_{0} \neq v_{1}[/tex]
