1.((17,65-9 1/4)*2,05-3,9*2/5):2,9=5,4
1)17,65-9 1/4=17 13/20-9 1/4=17 13/20-9 5/20=8 8/20=168/20=8,4
2)8,4*2,05=17,22
3)3,9*2/5=39/10*2/5=39/25
4)17,22-39/25=1722/100-39/25=1722/100-156/100=1566/100=15,66
5)15,66:2,9=5,4
2.((2/25*(9,5-6,85)+3 16/25:0,91)*3/4=3,159
1)9,5-6,85=2,65
2)2/25*2,65=0,08*2,65=0,212
3)3 16/25:0,91=91/25:91/100=91/25*100/91=4
4)0,212+4=4,212
5)4212/1000*3/4=3159/1000=3,159