Ответ:

-15

Пошаговое объяснение:

[tex]5-\frac{2}{5}*x=11\\\\\frac{2}{5}*x=5-11\\\\\frac{2}{5}*x=-6\\\\x=-6:\frac{2}{5}\\\\x=-\frac{6*5}{2}\\\\x=-15[/tex]