2 х+у=1 2 х^2+ху+у^2=1

система

2x+y=1 2x+y=1 2 (1-y²) + y=1 2-2y²+y-1=0

2x²+xy+y²=1 x (2x+y) + y²=1 x*1+y²=1 x=1-y²

-2y²+y+1=0

D=1²-4 * (-2) = 1+8=9=3²

y = (-1-3) / (-2*2) = 1 2x+1=1 2x=1-1 2x=0 x=0

y = (-1+3) / (-2*2) = - 1/2 2x + (-1/2) = 1 2x=1+1/2 2x=3/2 x=3/2:2=3/4