1*2+3+4-5+6+7-8 = 9
<span>1*2+3+4+56:7-8=9</span>
10 : 5/8 = 10 * 8/5 = 16
2 : 11/3 = 2 * 3/11 = 6/11
12 : 2 1/7 = 12 : (14/7+1/7) = 12 : 15/7 = 12 * 7/15 = 84/15 = 5 9/15 = 5 3/5
1)(4.2+2.1):2=6.3:2=3.15
2)(3.9+6+9+18+15.8):5=52.7:5=10.54
3) 1)56.4x3=169.2 км
2)62.7x4=250.8км
3) 169.2+250.8=420км
4)3+4=7ч
5)420:7=60км/ч
Ответ: 60км/ч