г) \( 0.6x - 5.4 = -0.8x + 5.8 \)\( 0.6x + 0.8x = 5.8 + 5.4 \)\( 1.4x = 11.2 \)\( x = \frac{11.2}{1.4} \)\( x = 8 \)
Ответ: x = 8