50400:12=<span>4200</span><span><span>
-24</span><span>
24</span><span>
<span>0
</span></span></span>31005:15=2067
-30
-100
90
-105
105
<span>223218:18= </span>124<span><span>
-43</span><span>
36</span><span>
-72</span><span>
72</span><span> <span>
0</span></span></span>
480640:16=30040
<span><span><span>-48
</span> 064<span>
-64</span><span>
0</span></span>
</span>
а) 3/4 * 5/7 = 15/28
б) 1/8 * 3/4 = 3/32
в) 4/7 * 5/6 = 20/42 = 10/21
г) 2/5 * 7/11 = 14/55
д) 1/2 * 4/9 = 4/18 = 2/9
е) 11/12 * 8/9 = 88/108 = 22/27
ж) 2/5 * 3/2 = 3/5
з) 11/15 * 3/5 = 11/5 * 1/5 = 11/25
и) 15/16 * 5/9 = 75/45 = 15/9 = 1целая6/9
40 мин 35 сек
_
20 мин 48 сек
____________
19 мин 87 сек
57 = 50+7, 36= 30+6, 28=20+8.
Нуу, наверное на 40 процентов