/·21
умножаем на 21 для того, чтобы избавиться от знаменателей
![3(x+9)=21+7(x+1) 3(x+9)=21+7(x+1)](https://tex.z-dn.net/?f=3%28x%2B9%29%3D21%2B7%28x%2B1%29)
![3x+27=21+7x+7 3x+27=21+7x+7](https://tex.z-dn.net/?f=3x%2B27%3D21%2B7x%2B7)
![3x+27=28+7x 3x+27=28+7x](https://tex.z-dn.net/?f=3x%2B27%3D28%2B7x)
![7x-3x=27-28 7x-3x=27-28](https://tex.z-dn.net/?f=7x-3x%3D27-28)
![4x=-1 4x=-1](https://tex.z-dn.net/?f=4x%3D-1)
![x=-1:4 x=-1:4](https://tex.z-dn.net/?f=x%3D-1%3A4)
![x=-\frac{1}{4}=-0,25 x=-\frac{1}{4}=-0,25](https://tex.z-dn.net/?f=x%3D-%5Cfrac%7B1%7D%7B4%7D%3D-0%2C25)
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/·18
умножаем на 18 для того, чтобы избавиться от знаменателей
![18-3(5x-2)=2(x-5) 18-3(5x-2)=2(x-5)](https://tex.z-dn.net/?f=18-3%285x-2%29%3D2%28x-5%29+)
![18-15x+6=2x-10 18-15x+6=2x-10](https://tex.z-dn.net/?f=18-15x%2B6%3D2x-10)
![24-15x=2x-10 24-15x=2x-10](https://tex.z-dn.net/?f=24-15x%3D2x-10)
![2x+15x=24+10 2x+15x=24+10](https://tex.z-dn.net/?f=2x%2B15x%3D24%2B10)
![17x=34 17x=34](https://tex.z-dn.net/?f=17x%3D34)
![x=34:17 x=34:17](https://tex.z-dn.net/?f=x%3D34%3A17)
![x=2 x=2](https://tex.z-dn.net/?f=x%3D2)
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/·10
умножаем на 10 для того, чтобы избавиться от знаменателей
![2(3x+4)+5(x-7)=4(2x+3) 2(3x+4)+5(x-7)=4(2x+3)](https://tex.z-dn.net/?f=2%283x%2B4%29%2B5%28x-7%29%3D4%282x%2B3%29)
![6x+8+5x-35=8x+12 6x+8+5x-35=8x+12](https://tex.z-dn.net/?f=6x%2B8%2B5x-35%3D8x%2B12)
![11x-27=8x+12 11x-27=8x+12](https://tex.z-dn.net/?f=11x-27%3D8x%2B12)
![11x-8x=12+27 11x-8x=12+27](https://tex.z-dn.net/?f=11x-8x%3D12%2B27)
![3x=39 3x=39](https://tex.z-dn.net/?f=3x%3D39)
![x=39:3 x=39:3](https://tex.z-dn.net/?f=x%3D39%3A3)
![x=13 x=13](https://tex.z-dn.net/?f=x%3D13)
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/·6
умножаем на 6 для того, чтобы избавиться от знаменателей
![3(7x-3)-2(9-4x)=3(7-x) 3(7x-3)-2(9-4x)=3(7-x)](https://tex.z-dn.net/?f=3%287x-3%29-2%289-4x%29%3D3%287-x%29)
![21x-9-18+8x=21-3x 21x-9-18+8x=21-3x](https://tex.z-dn.net/?f=21x-9-18%2B8x%3D21-3x)
![29x-27=21-3x 29x-27=21-3x](https://tex.z-dn.net/?f=29x-27%3D21-3x)
![29x+3x=21+27 29x+3x=21+27](https://tex.z-dn.net/?f=29x%2B3x%3D21%2B27)
![32x=48 32x=48](https://tex.z-dn.net/?f=32x%3D48)
![x=48:32 x=48:32](https://tex.z-dn.net/?f=x%3D48%3A32)
![x=1,5 x=1,5](https://tex.z-dn.net/?f=x%3D1%2C5)