0,9х-0,6*(х-3)=2*(0,2х-1,3)
0,9х-0,6х+1,8=0,4х-2,6
0,3х+1,8=0,4х-2,6
0,3х-0,4х=-2,6-1,8
-0,1х=-4,4
х=-4,4:(-0,1)
х=44
0,9*44-0,6*(44-3)=2*(0,2*44-1,3)
39,6-0,6*41=2*(8,8-1,3)
39,6-24,6=2*7,5
15=15
![y=2x-\frac{b}{3}](https://tex.z-dn.net/?f=+y%3D2x-%5Cfrac%7Bb%7D%7B3%7D++)
подставим координаты точки A(2;2)
![2=2*2-\frac{b}{3} \\ 2=4-\frac{b}{3}\\ \frac{b}{3}=2\\ b=6](https://tex.z-dn.net/?f=+2%3D2%2A2-%5Cfrac%7Bb%7D%7B3%7D+%5C%5C+2%3D4-%5Cfrac%7Bb%7D%7B3%7D%5C%5C+%5Cfrac%7Bb%7D%7B3%7D%3D2%5C%5C++b%3D6+)
1. (7m - n) + (49m^2 - n^2) = (7m-n) + (7m-n)(7m+n)=(7m-n)(7m-n+1)
2. 4 х^2 - 4 ху + у^2 - 16 = 4 х (х-у) + (у-4) (у+4) .
Вот................(.)(.)