![\sqrt[4]{21-10x}=12-\sqrt[4]{21-10x}](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7B21-10x%7D%3D12-%5Csqrt%5B4%5D%7B21-10x%7D)
ОДЗ:
21-10x>0
10x<21
x<2.1
![\sqrt[4]{21-10x}=12-\sqrt[4]{21-10x}\\2\sqrt[4]{21-10x}=12\\\sqrt[4]{21-10x}=6\\(\sqrt[4]{21-10x})^4=6^4\\|21-10x|=1296\\21-10x=1296\ \ \ ili\ \ \ 21-10x=-1296\\10x=-1275\ \ \ \ \ \ \ ili\ \ \ 10x=1317\\x=-127.5\ \ \ \ \ \ \ \ \ ili\ \ \ x=131.7](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7B21-10x%7D%3D12-%5Csqrt%5B4%5D%7B21-10x%7D%5C%5C2%5Csqrt%5B4%5D%7B21-10x%7D%3D12%5C%5C%5Csqrt%5B4%5D%7B21-10x%7D%3D6%5C%5C%28%5Csqrt%5B4%5D%7B21-10x%7D%29%5E4%3D6%5E4%5C%5C%7C21-10x%7C%3D1296%5C%5C21-10x%3D1296%5C+%5C+%5C+ili%5C+%5C+%5C+21-10x%3D-1296%5C%5C10x%3D-1275%5C+%5C+%5C+%5C+%5C+%5C+%5C+ili%5C+%5C+%5C+10x%3D1317%5C%5Cx%3D-127.5%5C+%5C+%5C+%5C+%5C+%5C+%5C+%5C+%5C+ili%5C+%5C+%5C+x%3D131.7)
x=131.7 не входит в область допустимых задач.
Ответ: x=-127.5
А)х=-14/-2, х=7
б)х=1/6/-6, х=-1/36
в)-0.7х=-7, х=-7/-0.7, х=10
г)9-35=26у-13у, -26=13у, у=-26/13, у=-2
д)6х+1-3+2х=14, 8х=14-1+3, 8х=16, х=2
У=2х+b
подставляем первые координаты
1=2х1+b
b=-1
1=2x4+b
b=-7
4=2x1+b
b=2
4=2x4+b
b-4