Solve the problems in the table 'устного счёта'.

Решение:

Левая часть (Таблица VI):

• \[ -\frac{1}{4} - 2 = -\frac{1}{4} - \frac{8}{4} = -\frac{9}{4} \]
• \[ -\frac{1}{4} + 1 = -\frac{1}{4} + \frac{4}{4} = \frac{3}{4} \]
• \[ -\frac{1}{4} + 2 = -\frac{1}{4} + \frac{8}{4} = \frac{7}{4} \]
• \[ -5\frac{1}{2} - 6\frac{1}{2} = -(\frac{11}{2} + \frac{13}{2}) = -\frac{24}{2} = -12 \]
• \[ -5\frac{1}{2} + 6\frac{1}{2} = -\frac{11}{2} + \frac{13}{2} = \frac{2}{2} = 1 \]
• \[ -3\frac{3}{4} + 6\frac{7}{8} = -\frac{15}{4} + \frac{55}{8} = -\frac{30}{8} + \frac{55}{8} = \frac{25}{8} \]
• \[ 16 - 17\frac{2}{3} = 16 - \frac{53}{3} = \frac{48}{3} - \frac{53}{3} = -\frac{5}{3} \]
• \[ -20 - 15\frac{3}{4} = -20 - \frac{63}{4} = -\frac{80}{4} - \frac{63}{4} = -\frac{143}{4} \]

Правая часть (Таблица VII):

• 1) \( -2x + 6x = 4x \)
• 2) \( -5y - y = -6y \)
• 3) \( 7x - 8x - 3x = -4x \)
• 4) \( -3x + 8x - 6x = -x \)
• 5) \( 2x - x + 10x = 11x \)
• 6) \( -7a + 3a + 4a = 0 \)
• 7) \( -3a + 6b - 4a - 3b = -7a + 3b \)
• 8) \( -3m - 2m - 4m = -9m \)
• 9) \( -4k + 3k - 6k + 7k = 0 \)
• 10) \( 3m - m + 4m = 6m \)
• 11) \( -\frac{1}{2}y + 5a - 6a = -\frac{1}{2}y - a \)
• 12) \( -\frac{1}{2}y + 5a - \frac{1}{2}y = -y + 5a \)