{ x * 0,01y = 400
{ (x + 400) + (x + 400) * 0,01y = 5832
y = 40000/x
x + 400 + (x + 400) * 400/x = 5832
x + 800 + 160000/x = 5832
x² + 800x - 5832x + 160000 = 0
x² - 5032x + 160000 = 0 D = b²-4ac = 25 321 024 - 640 000 = 4968²
x₁ = (-b+√D)/2a = (5032+4968)/2 = 5000
x₂ = (-b -√D)/2a = (5032-4968)/2 = 32
y₁ = 40 000 : 5 000 = 8
y₂ = 40 000 : 32 = 1250
Ответ: {5000; 8}, {32; 1250}