Помогите пожалуста 1085

1) 5/12a+7 ; a=4 5/12×4+7 5/12×48/12+7 240/12+7=20/1+7/1=27/1=27 2) 4/9b+2/3 ; b=6 4/9×6+2/3 4/9×54/9+2/3 216/9+2/3=72/3+2/3=74/3=24⅔