а) 3,4:20,4=

б)1,17:1 целую 4/5=

Уравнения:
х-7/9х=3,6

3,4:204=34/10 : 204/10=34/10 · 10/204=1/61,17: 1 4/5=117/100 : 9/5=117/100 · 5/9=117/180=0,65х- 7/9·х=3,69/9х-7/9х=3,62/9х=36/10х=36/10 : 2/9=36/10 · 9/2=162/10=16,2