пример 4/5 : 2 2/3 -0,12

1)4/5 : 2 2/3 = 4/5:  8/3 = 4/5  * 3/8 = 12/40= 3/10
2)3/10-0,12=3/10-12/100=3/10 - 3/25 =(3 * 5 - 3 * 2)/50 = 15/50 -6/50 =  9/50