линеечку приложим: 160см ~ 20мм, х ~ 55мм, х=440см=4.4м
<span>91 * 2/5 :5 3/5 + 3 48/100 : 6/25=21
1) 91*2/5=182/5
2) 182/5: 5 3/5=182/5:28/5=182*5/5*28=13/2
3) 3 48/100:6/25=348/100*25/6=29/2
4) 13/2+29/2=42/2=21</span>
568 + (4753 - 642) - 450 : 9 × 6 = 4 379
1) 450 : 9 = 50
2) 50 × 6 = 300
3) 4753 - 642 = 4111
4) 568 + 4111 = 4679
5) 4679 - 300 = 4379