2номер 19 и номер 20

№ 19

2/47*9,4+5,6=2/47*94/10+56/10=2/5+56/10=4/10+56/10=60/10=6
2,1-6,2*3/31=21/10-62/10*3/31=21/10-6/10=15/10=3/2 1 1/2
5,8:9 2/3+8,04=58/10:29/3-804/100=58/10*3/29-804/100=6/10-804/100=60/100-804/100=744/100=7 44/100=7,44