Контрольные задания > 1356. Решите уравнение: 1) 2,5x=-1; 2) 0,3x = 1; 3) 7x = -3; 4) -16x = 8; 5) |x| - 5 = 0; 6) |x| + 3,2 = 8; 7) 4,1 - |x| = 5; 8) |3x + 1,8| = 0; 9) 9|x| - 6 = 0; 10) 8/x = 6/5; 11) 7/4 = x/2; 12) (x+3)/12 = 4/3; 13) 7x = x + 25; 14) 0,4x - 6 = 0,6x – 9; 15) 3x + 16 = 9 - 10x; 16) 0,6(x + 1 2/3) = -1,2; 17) -3,4(x + 9 3/11) = -68; 18) x/3 + x/4 = -21; 19) 2m/3 - 4m/5 = 3; 20) (4a/9) - 1 = (5a/12); 21) 3(1 - x) + 5(x + 2) = 1 - 4x; 22) 3(2-x) - (5x + 4) = 0,4 - 16x; 23) 2(3-5p) = 4(1-p) - 1; 24) 0,5(2y - 1) - (0,5 – 0,2y) + 1 = 0; 25) -4(5-2m) + 3(m - 4) = 6(2-m) – 5m;
Вопрос:

1356. Решите уравнение: 1) 2,5x=-1; 2) 0,3x = 1; 3) 7x = -3; 4) -16x = 8; 5) |x| - 5 = 0; 6) |x| + 3,2 = 8; 7) 4,1 - |x| = 5; 8) |3x + 1,8| = 0; 9) 9|x| - 6 = 0; 10) 8/x = 6/5; 11) 7/4 = x/2; 12) (x+3)/12 = 4/3; 13) 7x = x + 25; 14) 0,4x - 6 = 0,6x – 9; 15) 3x + 16 = 9 - 10x; 16) 0,6(x + 1 2/3) = -1,2; 17) -3,4(x + 9 3/11) = -68; 18) x/3 + x/4 = -21; 19) 2m/3 - 4m/5 = 3; 20) (4a/9) - 1 = (5a/12); 21) 3(1 - x) + 5(x + 2) = 1 - 4x; 22) 3(2-x) - (5x + 4) = 0,4 - 16x; 23) 2(3-5p) = 4(1-p) - 1; 24) 0,5(2y - 1) - (0,5 – 0,2y) + 1 = 0; 25) -4(5-2m) + 3(m - 4) = 6(2-m) – 5m;

Смотреть решения всех заданий с листа

Ответ:

Решим уравнения:

  1. 2.5x = -1 \(x = \frac{-1}{2.5} = -\frac{10}{25} = -\frac{2}{5} = -0.4\)
  2. 0.3x = 1 \(x = \frac{1}{0.3} = \frac{10}{3} = 3\frac{1}{3}\)
  3. 7x = -3 \(x = -\frac{3}{7}\)
  4. -16x = 8 \(x = \frac{8}{-16} = -\frac{1}{2} = -0.5\)
  5. \(|x| - 5 = 0\) \(|x| = 5\) \(x = 5\) или \(x = -5\)
  6. \(|x| + 3.2 = 8\) \(|x| = 8 - 3.2\) \(|x| = 4.8\) \(x = 4.8\) или \(x = -4.8\)
  7. \(4.1 - |x| = 5\) \(-|x| = 5 - 4.1\) \(-|x| = 0.9\) \(|x| = -0.9\) - решений нет, так как модуль не может быть отрицательным.
  8. \(|3x + 1.8| = 0\) \(3x + 1.8 = 0\) \(3x = -1.8\) \(x = \frac{-1.8}{3} = -0.6\)
  9. \(9|x| - 6 = 0\) \(9|x| = 6\) \(|x| = \frac{6}{9} = \frac{2}{3}\) \(x = \frac{2}{3}\) или \(x = -\frac{2}{3}\)
  10. \(\frac{8}{x} = \frac{6}{5}\) \(6x = 8 \cdot 5\) \(6x = 40\) \(x = \frac{40}{6} = \frac{20}{3} = 6\frac{2}{3}\)
  11. \(\frac{7}{4} = \frac{x}{2}\) \(4x = 7 \cdot 2\) \(4x = 14\) \(x = \frac{14}{4} = \frac{7}{2} = 3.5\)
  12. \(\frac{x+3}{12} = \frac{4}{3}\) \(3(x + 3) = 12 \cdot 4\) \(3x + 9 = 48\) \(3x = 48 - 9\) \(3x = 39\) \(x = \frac{39}{3} = 13\)
  13. \(7x = x + 25\) \(7x - x = 25\) \(6x = 25\) \(x = \frac{25}{6} = 4\frac{1}{6}\)
  14. \(0.4x - 6 = 0.6x - 9\) \(0.4x - 0.6x = 6 - 9\) \(-0.2x = -3\) \(x = \frac{-3}{-0.2} = \frac{30}{2} = 15\)
  15. \(3x + 16 = 9 - 10x\) \(3x + 10x = 9 - 16\) \(13x = -7\) \(x = -\frac{7}{13}\)
  16. \(0.6(x + 1\frac{2}{3}) = -1.2\) \(0.6(x + \frac{5}{3}) = -1.2\) \(x + \frac{5}{3} = \frac{-1.2}{0.6} = -2\) \(x = -2 - \frac{5}{3} = -2 - 1\frac{2}{3} = -3\frac{2}{3}\)
  17. \(-3.4(x + 9\frac{3}{11}) = -68\) \(x + 9\frac{3}{11} = \frac{-68}{-3.4} = 20\) \(x = 20 - 9\frac{3}{11} = 10\frac{8}{11}\)
  18. \(\frac{x}{3} + \frac{x}{4} = -21\) \(\frac{4x + 3x}{12} = -21\) \(7x = -21 \cdot 12\) \(x = \frac{-21 \cdot 12}{7} = -3 \cdot 12 = -36\)
  19. \(\frac{2m}{3} - \frac{4m}{5} = 3\) \(\frac{10m - 12m}{15} = 3\) \(-2m = 3 \cdot 15\) \(m = \frac{45}{-2} = -22.5\)
  20. \(\frac{4a}{9} - 1 = \frac{5a}{12}\) \(\frac{4a}{9} - \frac{5a}{12} = 1\) \(\frac{16a - 15a}{36} = 1\) \(a = 36\)
  21. \(3(1 - x) + 5(x + 2) = 1 - 4x\) \(3 - 3x + 5x + 10 = 1 - 4x\) \(2x + 13 = 1 - 4x\) \(6x = -12\) \(x = -2\)
  22. \(3(2 - x) - (5x + 4) = 0.4 - 16x\) \(6 - 3x - 5x - 4 = 0.4 - 16x\) \(2 - 8x = 0.4 - 16x\) \(8x = -1.6\) \(x = -0.2\)
  23. \(2(3 - 5p) = 4(1 - p) - 1\) \(6 - 10p = 4 - 4p - 1\) \(6 - 10p = 3 - 4p\) \(-6p = -3\) \(p = 0.5\)
  24. \(0.5(2y - 1) - (0.5 - 0.2y) + 1 = 0\) \(y - 0.5 - 0.5 + 0.2y + 1 = 0\) \(1.2y = 0\) \(y = 0\)
  25. \(-4(5 - 2m) + 3(m - 4) = 6(2 - m) - 5m\) \(-20 + 8m + 3m - 12 = 12 - 6m - 5m\) \(-32 + 11m = 12 - 11m\) \(22m = 44\) \(m = 2\)
ГДЗ по фото 📸
Подать жалобу Правообладателю