ekaterinaan Приводим к знам 8
6*6/8 * 5*2/8 - 4*5/8 * 5*3/8 =
=36/8 * 10/8 - 20/8 * 15/8=
= (36*10-20*15) / 8 =
= 60 / 8 = 7,5