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x in (-oo:+oo)
21*x-x^2+4*x-((6*y)/(-50))+3*y = 14 // - 14
21*x-x^2+4*x-((6*y)/(-50))+3*y-14 = 0
21*x-x^2+4*x+(3/25)*y+3*y-14 = 0
25*x-x^2+78/25*y-14 = 0
DELTA = 25^2-(-1*4*(78/25*y-14))
DELTA = 4*(78/25*y-14)+625
4*(78/25*y-14)+625 = 0
4*(78/25*y-14)+625 = 0
312/25*y+569 = 0
312/25*y+569 = 0
312/25*y+569 = 0 // - 569
312/25*y = -569 // : 312/25
y = -569/312/25
y = -14225/312
DELTA = 0 <=> t_1 = -14225/312
x = -25/(-1*2) i y = -14225/312
x = 25/2 i y = -14225/312
( x = ((4*(78/25*y-14)+625)^(1/2)-25)/(-1*2) or x = (-(4*(78/25*y-14)+625)^(1/2)-25)/(-1*2) ) i y > -14225/312
( x = ((4*(78/25*y-14)+625)^(1/2)-25)/(-2) or x = ((4*(78/25*y-14)+625)^(1/2)+25)/2 ) i y > -14225/312
y+14225/312 > 0
y+14225/312 > 0 // - 14225/312
y > -14225/312
x in { 25/2, ((4*(78/25*y-14)+625)^(1/2)-25)/(-2), ((4*(78/25*y-14)+625)^(1/2)+25)/2 }
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