![\frac{(n+1)!}{n!} = \frac{(n+1)*n!}{n!} =n+1 ](https://tex.z-dn.net/?f=+%5Cfrac%7B%28n%2B1%29%21%7D%7Bn%21%7D+%3D+%5Cfrac%7B%28n%2B1%29%2An%21%7D%7Bn%21%7D+%3Dn%2B1%0A%0A%0A%0A%0A%0A%0A+)
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![\frac{(n+1)!(n+3)}{(n+4)!}=\frac{1}{(n+2)(n+4)}](https://tex.z-dn.net/?f=++%5Cfrac%7B%28n%2B1%29%21%28n%2B3%29%7D%7B%28n%2B4%29%21%7D%3D%5Cfrac%7B1%7D%7B%28n%2B2%29%28n%2B4%29%7D+)
75 рублей - 100%
72 рубля - х%
по пропорции х=(72*100)/75=96%
100% - 96% = 4%
Ответ: 4%
Х^2-2х+3х-6-(х^2+2х-3х-6)-5=6х-7
х^2-2х+3х-6-х^2-2х+3х+6-5-6х+7=0
-4х+6х-5-6х+7=0
-4х=-2
х=0,5
Для построения прямой достаточно двух точек
<span>1)у=-0,5х </span>
х=0 у=0
х=2 у=-1
2)у=3
(0;3) (5;3) (10; 3)