Решить систему уравнений 2 у-х=7 и х*х-ху-у*у=20

{2y-x=7

{x²-xy-y²=20

x = (2y-7)

(2y-7) ²-y (2y-7) - y²=20

4y²-28y+49-2y²+7y-y²-20=0

y²-21y+29=0

D = (-21) - 4*1*29=441-116=325=√325=18,028²

y1 = ( - (-21) + 18,028) / 2*1=39,028/2

y1=19,514

y2 = ( - (-21) - 18,028) / 2=2,972/2

y2=1,486

x1 = (2y1-7) = 2*19,514-7=39,028-7

x1=32,028

x2 = (2y2-7) = 2*1,486-7=2,972-7

x2=-4,028