1. Найдите значение выражения 7x - (x + 8) при x = -3.

1. 7x - (x + 8) = 6x - 8. При x = -3: 6 * (-3) - 8 = -18 - 8 = -26. 2. 6x - (x - 3) = 5x + 3. При x = -7: 5 * (-7) + 3 = -35 + 3 = -32. 3. 7x - (x - 9) = 6x + 9. При x = -7: 6 * (-7) + 9 = -42 + 9 = -33. 4. x - 8(x - 9) = x - 8x + 72 = -7x + 72. При x = -2: -7 * (-2) + 72 = 14 + 72 = 86. 5. x - 6(x - 5) = x - 6x + 30 = -5x + 30. При x = -6: -5 * (-6) + 30 = 30 + 30 = 60. 6. x - 8(x + 3) = x - 8x - 24 = -7x - 24. При x = -2: -7 * (-2) - 24 = 14 - 24 = -10. 7. 8x - 13 = 3x + 9 => 5x = 22 => x = 4.4. 8. -6x + 4 = 10x - 8 => -16x = -12 => x = 0.75. 9. -6x - 14 = -8x - 1 => 2x = 13 => x = 6.5. 10. -6.6x + 1.5 = -0.1x - 3.7 => -6.5x = -5.2 => x = 0.8. 11. -6.9x - 7.7 = -3.9x + 6.7 => -3x = 14.4 => x = -4.8. 12. -3.3x + 6.2 = -3.9x + 2.3 => 0.6x = -3.9 => x = -6.5.