7х-9у=11 -9у=11-7х у=(7/9)х-(11/9)=(7/9)х-1 2/9
15х-12у=0 12у=15х у=(15/12)х=1,25х
2х+3у=57 3у=57-2х у=19-(2/3)х
(x-11):(x-11)²/(x+11)=(x-11)(x+11)/(x-11)²=(x+11)/(x-11)
x=7
(7+11)/(7-11)=18/(-4)=-4,5
<span>16-9,5у=3у+21
16 -21 = 3y +9.5y
-5 = 12.5y
y =-5 /12.5 = -0.4</span>
49y^2-y^4=y^2(49-y^2)=y^2(7-y)(7+y).
x 1 2
y 2 6
http://prntscr.com/lfzx44