Помогите решить систему уравнений x+y=13 √ x+√ y=5

x+y=13 √ x+√ y=5 x+y=13 (√ x+√ y)^2 = 25 x + y = 13 x + y + 2√(xy) = 25 x + y = 13 2√(xy) = 25 - 13 x + y = `3 2√(xy) = 12 x + y = 13 √(xy) = 6 x + y = 13 xy = 36 y = 13 - x x*(13 - x) = 36 x^2 - 13x + 36 = 0 D = 169 - 4*1*36 = 169 - 144 = 25 x1 = (13 - 5)/2 x1 = 8/2 x1 = 4 x2 = (13 + 5)/2 x2 = 18/2 x2 = 9 y1 = 13 - 4 y2 = 9 y2 = 13 - 9  y2 = 4 Ответ: (4;9)  или (9;4)