1)ОДЗ:![x^2-2x>0\\x^2-2x=0\\x_1=0;x_2=2](https://tex.z-dn.net/?f=x%5E2-2x%3E0%5C%5Cx%5E2-2x%3D0%5C%5Cx_1%3D0%3Bx_2%3D2)
\\\+\\\(0)...-...(2)\\\+\\\=>
![x\in(-\infty;0)\cup(2;+\infty)](https://tex.z-dn.net/?f=x%5Cin%28-%5Cinfty%3B0%29%5Ccup%282%3B%2B%5Cinfty%29)
![log_2(x^2-2x)=3\\x^2-2x-8=0\\x_1=4\ ;x_2=-2](https://tex.z-dn.net/?f=log_2%28x%5E2-2x%29%3D3%5C%5Cx%5E2-2x-8%3D0%5C%5Cx_1%3D4%5C+%3Bx_2%3D-2)
2)ОДЗ:![\begin{cases} -x>0\\x+6>0 \end{cases}\ \begin{cases} x<0\\x>-6 \end{cases}\\\\x\in(-6;0)](https://tex.z-dn.net/?f=%5Cbegin%7Bcases%7D+-x%3E0%5C%5Cx%2B6%3E0+%5Cend%7Bcases%7D%5C+%5Cbegin%7Bcases%7D+x%3C0%5C%5Cx%3E-6+%5Cend%7Bcases%7D%5C%5C%5C%5Cx%5Cin%28-6%3B0%29)
![2log_3(-x)=1+log_3(x+6)\\log_3(-x)^2=log_33+log_3(x+6)\\x^2-3x-18=0\\x_1=6error\ ;x_2=-3](https://tex.z-dn.net/?f=2log_3%28-x%29%3D1%2Blog_3%28x%2B6%29%5C%5Clog_3%28-x%29%5E2%3Dlog_33%2Blog_3%28x%2B6%29%5C%5Cx%5E2-3x-18%3D0%5C%5Cx_1%3D6error%5C+%3Bx_2%3D-3)
3)![log_327-log_{\frac{1}{7}}7=3-(-1)=4](https://tex.z-dn.net/?f=log_327-log_%7B%5Cfrac%7B1%7D%7B7%7D%7D7%3D3-%28-1%29%3D4)
4)![2^{1+log_25}=2+5=7](https://tex.z-dn.net/?f=2%5E%7B1%2Blog_25%7D%3D2%2B5%3D7)
5)![lg4+2lg5=lg4+lg25=lg100=2](https://tex.z-dn.net/?f=+lg4%2B2lg5%3Dlg4%2Blg25%3Dlg100%3D2)
6)![log_5\sqrt{10} - log_5\sqrt{2}=log_5\sqrt{5}=0.5](https://tex.z-dn.net/?f=+log_5%5Csqrt%7B10%7D+-+log_5%5Csqrt%7B2%7D%3Dlog_5%5Csqrt%7B5%7D%3D0.5)
11+x/41+x=3/8 3·(41+х)=8·(11+х)- метод пропорции 123+3x=88 +8x 5x=35 x=7
Y1=(30+√(30^2-4*9*25))/2*9=
=(30-0)/18=30/18=5/3=1 2/3
можно посчитать в уме 4.2 2.4 0.6 -1.2 -3 -4.8 шестой
можно по формулам
an=a1+(n-1)*d
a1=4.2
d=a2-a1=2.4-4.2=-1.8
-4.8=4.2+(n-1)*(-1.8)
-9=(n-1)*(-1.8)
5=n-1
n=6
А. 13%, все кто записались, а 35% это часть уже из записанных