4)
3451 : 17 = 3400:17 + 51:33 = 200+3 = 203
7744 : 11 = 7700 : 11 + 44:11 = 700 +4 = 704
5684 : 28 = 203
2842 : 14 = 200 + 3 = 203
1 1/3х + 0,2 = 1
4/3х = 1 - 1/5
4/3х = 4/5
х = 4/5 : 4/3
х = 3/5 = 0,6
![lg(x-5)-lg \sqrt{5x-10}=0](https://tex.z-dn.net/?f=lg%28x-5%29-lg+%5Csqrt%7B5x-10%7D%3D0++)
ОДЗ:
![\left \{ {{x-5\ \textgreater \ 0} \atop {5x-10\ \textgreater \ 0}} \right. \Rightarrow \left \{ {{x\ \textgreater \ 5} \atop {x\ \textgreater \ 2}} \right.](https://tex.z-dn.net/?f=+%5Cleft+%5C%7B+%7B%7Bx-5%5C+%5Ctextgreater+%5C+0%7D+%5Catop+%7B5x-10%5C+%5Ctextgreater+%5C+0%7D%7D+%5Cright.+%5CRightarrow++%5Cleft+%5C%7B+%7B%7Bx%5C+%5Ctextgreater+%5C+5%7D+%5Catop+%7Bx%5C+%5Ctextgreater+%5C+2%7D%7D+%5Cright.+)
x∈(5;+∞)
![lg \frac{x-5}{ \sqrt{5x-10} }=0 \\ \\ \frac{x-5}{ \sqrt{5x-10} }=1 \\ \\ x-5= \sqrt{5x-10} \\ \\ x^2-10x+25=5x-10](https://tex.z-dn.net/?f=lg+%5Cfrac%7Bx-5%7D%7B+%5Csqrt%7B5x-10%7D+%7D%3D0+%5C%5C++%5C%5C++%5Cfrac%7Bx-5%7D%7B+%5Csqrt%7B5x-10%7D+%7D%3D1+%5C%5C++%5C%5C+x-5%3D+%5Csqrt%7B5x-10%7D++%5C%5C++%5C%5C+x%5E2-10x%2B25%3D5x-10+)
x²-15x+35=0
D=225-140=85
x=(15+√85)/2 или х=(15-√85)/2<5 и поэтому не входит в ОДЗ
Ответ.x=(15+√85)/2