Ответ:

  1. 3x + 7 = 0 → 3x = −7 → x = −7/3.

  2. 13 − 100x = 0 → −100x = −13 → x = 0,13.

  3. 7x − 4 = x − 16 → 6x = −12 → x = −2.

  4. 13 − 5x = 8 − 2x → 5 = 3x → x = 5/3.

  5. 4y + 15 = 6y + 17 → −2 = 2y → y = −1.

  6. 5x + (3x − 7) = 9 → 8x = 16 → x = 2.

  7. 3y − (5 − y) = 11 → 4y − 5 = 11 → y = 4.

  8. (7x + 1) − (6x + 3) = 5 → x − 2 = 5 → x = 7.

  9. (8x + 11) − 13 = 9x − 5 → 8x − 2 = 9x − 5 → x = 3.

  10. 0,5x + 0,15 = 0 → 0,5x = −0,15 → x = −0,3.

  11. 8 − 0,8x = 0 → 0,8x = 8 → x = 10.

  12. 1,3p − 11 = 0,8p + 5 → 0,5p = 16 → p = 32.

  13. 0,71x − 13 = 10 − 0,29x → x = 23.

  14. 8c + 0,73 = 4,61 − 8c → 16c = 3,88 → c = 0,2425.

  15. 48 = 11 − (9a + 2) → 48 = 9 − 9a → a = −13/3.

  16. 13 − (5x + 11) = 6x → 2 − 5x = 6x → x = 2/11.

  17. 2 = (3x − 5) − (7 − 4x) → 2 = 7x − 12 → x = 2.

  18. 8x + 5 = 119 + (7 − 3x) → 11x = 121 → x = 11.