2. а) \[ 4x + 6 - x = (4 - 1)x + 6 = 3x + 6 \]
2. б) \[ 7x - 8 + 5x = (7 + 5)x - 8 = 12x - 8 \]
2. в) \[ x - 5 + 3x = (1 + 3)x - 5 = 4x - 5 \]
2. г) \[ -7x + 9 + 7x = (-7 + 7)x + 9 = 0x + 9 = 9 \]
2. д) \[ x + 2 - 4x = (1 - 4)x + 2 = -3x + 2 \]
2. е) \[ -8x - 7 + 8x = (-8 + 8)x - 7 = 0x - 7 = -7 \]
Ответ: