Помогите!!! 7 7/9(5/7-2 9/14)

7 целых 7 / 9 * ( 5 / 7 - 2 целых 9 / 14 ) = ( 7 * 9 + 7 ) / 9 * ( 5 / 7 - 2 целых 9 / 14 ) = ( 63 + 7 ) / 9 * ( 5 / 7 - 2 целых 9 / 14 ) = 70 / 9 * ( 5 / 7 - 2 целых 9 / 14 ) = 70 / 9 * ( 5 / 7 - ( 2 * 14 + 9 ) / 14 ) = 70 / 9 * ( 5 / 7 - ( 28 + 9 ) / 14 ) = 70 / 9 * ( 5 / 7 - 37 / 14 ) = 70 / 9 * ( 5 * 2 - 37 * 1) / 14 = 70 / 9 * ( 10 - 37 ) / 14 = 70 / 9 * ( - 27 / 14 ) = - ( 70 * 27 ) / ( 9 * 14 ) = - ( 7 * 10 * 27 ) / ( 9 * 7 * 2 ) = - ( 1 * 10 * 27 ) / (9 * 1 * 2 ) = - (10 * 27 ) / ( 9 * 2 ) = - ( 5 * 2 * 9 * 3 ) / ( 9 * 2 ) = - ( 5 * 1 * 3 ) / ( 1 * 1 ) = - 5 * 3= - 15.