Ответ:

  1. а) 2x = ⅓; x = ⅓ : 2 = ⅙.
  2. б) 27 − 31 = x + 4x; −4 = 5x; x = −⅘.
  3. в) 7x = −5; x = −5⁄7.
  4. г) 3x − 7x + 2 = 18; −4x = 16; x = −4.