1.Use the alogorithm for solving a quartic.
2.Use a computer.
2.
[tex]27x^4+\allowbreak 3.\,886x-0.9715=0[/tex]
Solution is : [tex]\left\{ x\simeq .\,17958\,83748\,64723\,92446\,37443\,25198+.\,48229\,37667\,81214\,05384\,75340\,03169i\right\} ,[/tex]
[tex]\allowbreak \left\{ x\simeq .\,17958\,83748\,64723\,92446\,37443\,25198-.\,48229\,37667\,81214\,05384\,75340\,03169i\right\} ,\allowbreak[/tex]
[tex]\left\{ x\simeq .\,23041\,56601\,18966\,06539\,90038\,76249\right\} ,[/tex]
[tex]\allowbreak \left\{ x\simeq -.\,58959\,24098\,48413\,91432\,64925\,26645\right\}[/tex]
Daniel.