Пошаговое объяснение:
2/3x - 1 4/21x = 2 13/21 + 3/7
14/21x - 25/21x = 2 13/21 + 9/21
-11/21x = 2 22/21
-11/21x = 64/21
-x = 64/21 : 11/21
-x = 64/21 * 21/11
-x = 64/11
x = - 5 9/11
