1. 6! = 1·2·3·4·5·6=720
2. =n! / (n-k)! = 4! / (4-3)! = 24
<span>1 1/22 *3 2/3 -(2 5/6+3 5/6*7/23)*3/5 = 1 13/30
1) 3 5/6 * 7/23 = 23/6 * 7/23 = 7/6
2) 2 5/6 + 7/6 = 17/6 + 7/6 = 24/6 = 4
3) 1 1/22 * 3 2/3 = 23/22 * 11/3 = 23/2 * 1/3 = 23/6
4) 4 * 3/5 = 12/5
5) 23/6 - 12/5 = 115/30 - 72/30 = 43/30 = 1 13/30</span>
![8*(112-5x)=816\\112-5x=816:8\\112-5x=102 \\ 5x=112-102 \\ 5x=10\\x=10:5\\x=2](https://tex.z-dn.net/?f=8%2A%28112-5x%29%3D816%5C%5C112-5x%3D816%3A8%5C%5C112-5x%3D102+%5C%5C+5x%3D112-102+%5C%5C+5x%3D10%5C%5Cx%3D10%3A5%5C%5Cx%3D2+)
17,4 м = 17,4*10 дм = 174 дм
6,25 м = 6,25*10 дм =62,5 дм
1)
![174*62,5=10875](https://tex.z-dn.net/?f=174%2A62%2C5%3D10875)
2)
![10875:5=2175](https://tex.z-dn.net/?f=10875%3A5%3D2175)
(плиток)
Ответ: 2175 плиток