Что возвести в степень ? 1 во второй степени - 1 , 2 во второй степени - 4 ,
![5-2x=11-7(x+2)](https://tex.z-dn.net/?f=5-2x%3D11-7%28x%2B2%29)
![5-2x=11-7x-14](https://tex.z-dn.net/?f=5-2x%3D11-7x-14)
![5-2x=-3-7x](https://tex.z-dn.net/?f=5-2x%3D-3-7x)
![7x-2x=-3-5](https://tex.z-dn.net/?f=7x-2x%3D-3-5)
![5x=-8](https://tex.z-dn.net/?f=5x%3D-8)
![x=-8:5](https://tex.z-dn.net/?f=x%3D-8%3A5)
![x=-\frac{8}{5}=-1,6](https://tex.z-dn.net/?f=x%3D-%5Cfrac%7B8%7D%7B5%7D%3D-1%2C6)
_________________________________________________________
(это проверка)
![5+3,2=11-7\cdot0,4](https://tex.z-dn.net/?f=5%2B3%2C2%3D11-7%5Ccdot0%2C4)
![8,2=11-2,8](https://tex.z-dn.net/?f=8%2C2%3D11-2%2C8)
![8,2=8,2](https://tex.z-dn.net/?f=8%2C2%3D8%2C2)
16(25c^2+70c+49)-81=0
400c^2+1120c+784-81=0
400c^2+1120c+703=0
D=1120^2-4*400*703=1254400-1124800=129600=360^2
x1=(-1120-360):800=-1.85
x2=(-1120+360):800=-0.95
Ответ: -1,85 и -0,95