1)x=6/6,5
x=0.92(целое число 0.92307692, но я округлил)
3)x= -0,077/(-0,01)=7.7
5)x=28/(56/17)=8,5
<span>10801-x=5400
х=</span>10801-5400
х=5401
<span>1703+x=1213+490
</span>1703+x=1703
х=0
<span>x:3-18=12
</span>х;3=18+12
х:3=30
х=90
<span>5*x+80=690
</span>5*х=690-80
5*х=610
х=610:5
х=122
<span>x*8+120=280
</span>х*8=280-120
х*8=160
х=160:8
х=20.
<span>(y-35)+12=32
у-35=32-12
у-35=20
у=35+20
у=55
_____________
(55-35)+12=32</span>
![\begin{cases}\frac{x-2}{x^2-3x-10}\geq0\\x^2-3x-10\neq0\end{cases}\\x^2-3x-10=0\\D=9+4\cdot10=49\\x_1=-2,\;x_2=5](https://tex.z-dn.net/?f=%5Cbegin%7Bcases%7D%5Cfrac%7Bx-2%7D%7Bx%5E2-3x-10%7D%5Cgeq0%5C%5Cx%5E2-3x-10%5Cneq0%5Cend%7Bcases%7D%5C%5Cx%5E2-3x-10%3D0%5C%5CD%3D9%2B4%5Ccdot10%3D49%5C%5Cx_1%3D-2%2C%5C%3Bx_2%3D5)
Первое неравенство выполняется в двух случаях - когда и числитель и знаменатель положительны, и когда они оба отрицательны.
![1,\;\begin{cases}x-2\geq0\\x^2-3x-10>0\end{cases}\Rightarrow\begin{cases}x\geq2\\(x+2)(x-5)>0\end{cases}\Rightarrow x\in(5\;+\infty)\\2.\;\begin{cases}x-2\leq0\\x^2-3x-10<0\end{cases}\Rightarrow\begin{cases}x\leq2\\(x+2)(x-5)<0\end{cases}\Rightarrow x\in(-2;\;2]\\OTBET:\;x\in(-2;\;2]\cup(5;\;+\infty)](https://tex.z-dn.net/?f=1%2C%5C%3B%5Cbegin%7Bcases%7Dx-2%5Cgeq0%5C%5Cx%5E2-3x-10%3E0%5Cend%7Bcases%7D%5CRightarrow%5Cbegin%7Bcases%7Dx%5Cgeq2%5C%5C%28x%2B2%29%28x-5%29%3E0%5Cend%7Bcases%7D%5CRightarrow+x%5Cin%285%5C%3B%2B%5Cinfty%29%5C%5C2.%5C%3B%5Cbegin%7Bcases%7Dx-2%5Cleq0%5C%5Cx%5E2-3x-10%3C0%5Cend%7Bcases%7D%5CRightarrow%5Cbegin%7Bcases%7Dx%5Cleq2%5C%5C%28x%2B2%29%28x-5%29%3C0%5Cend%7Bcases%7D%5CRightarrow+x%5Cin%28-2%3B%5C%3B2%5D%5C%5COTBET%3A%5C%3Bx%5Cin%28-2%3B%5C%3B2%5D%5Ccup%285%3B%5C%3B%2B%5Cinfty%29)