(12,4 - 6 1/5) : 7 3/4 помогите плиз

12 4/10 - 6 1/5=124/10 - 31/5= (124 - 31.2)/10=62/107 3/4 = (7.4 +3)/4=31/462/10 : 31/4 = 62/10 . 4/31 = 8/10 = 0,8