0,8х - 3/0,3 = 0,6х - 8,4/ -9
0,8х - 10 = 0,6х + 8ц. 2/5/ 9
0,8х - 10 = 0,6х + 14/15
0,8х - 0,6х = 10 + 14/15
2/10х = 10ц.14/15
х = 54ц.2/3
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Проверка:
8/10* 54ц2/3 - 3/0,3 = 6/10*54ц 2/3 - 84/10: - 9
656/15 - 10 = 164/5 + 84/90
43ц.11/15 - 10 = 164/5 + 14/15
33ц 11/15 = 33ц 11/15