{ a + b = 50
{ ab + 11 = a² - b²
{ a = 50 - b
{ b(50 - b) + 11 = (50 - b)² - b²
50b - b² + 11 = 2500 - 100b + b² - b²
-b² + 150b - 2489 = 0
D = 22500 - 9956 = 12544 = 112²
b₁ = (-b+√D)/2a = (-150+112)/-2 = 19
b₂ = (-b-√D)/2a = (-150-112)/-2 = 131
a₁ = 50 - b₁ = 50 - 19 = 31
a₂ = 50 - b₂ = 50 - 131 = -81
Ответ: {31; 19},{-81; 131}