5x+74,7:1,4=x-84,9:2,1
5х + 53 5/14 = х - 40 3/7
5х - х = - 40 3/7 - 53 5/14
4х = - 40 6/14 - 53 5/14
4х = - 93 11/14
х = - 93 11/14 ÷ 4 = -1313/14 × 1/4 = -1313/56
х = -23 целых 25/56
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Проверка:
5 × (-1313/56) + 74,7:1,4= -1313/56 - 84,9:2,1
-117 13/56 + 53 5/14 = -23 25/56 - 40 3/7
-63 7/8 = -63 - 25/56 - 24/56
-63 7/8 = -63 49/56
-63 7/8 = -63 7/8
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решение верное!