2 целых 7 / 15 - 3 целых 1 / 5 х = 2 целых 1 / 15 х - 1 целая 4 / 5( 2 * 15 + 7 ) / 15 - ( 3 * 5 + 1 ) / 5 * х = ( 2 * 15 + 1 ) / 15 * х - ( 1 * 5 + 4 ) / 5 ( 30 + 7 ) / 15 - ( 15 + 1 ) / 5 * х = ( 30 + 1 ) / 15 * х - ( 5 + 4 ) / 5 37 / 15 - 16 / 5 * х = 31 / 15 * х - 9 / 5 - 16 / 5 * х - 31 / 15 * х = - 9 / 5 - 37 / 15 х * ( 16 / 5 + 31 / 15 ) = 9 / 5 + 37 / 15х * ( 16 * 3 + 31 * 1 ) / 15 = ( 9 * 3 + 37 * 1 ) / 15 х * ( 48 + 31 ) / 15 = ( 27 + 37 ) / 15 х * ( 48 + 31 ) = 27 + 37 х * 79 = 64х = 64 / 79