Найдите область определения функции y = (5/(x+6))-(Sqrt[4-7x])

 y=(5/(x+6))-√(4-7x)
{4-7х≥0  { -7x≥-4   { x≤4/7
  x≠-6 ,      x≠-6,       x≠0
 
-------------------  -6--------------------------- 4/7-----------------------gt;x
\\\\\\\\\\\\\\\\\\\\\\\\\\\  \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
Ответ:(-∞;-6)∪(-6;4/7]