х+у=48

х*у=15

х=?

у=?

х+у=48

ху=15

x=48-y

xy=15

(48-y) y=15

48y-y²=15

y²-48y+15=0

Δ = (-48) ²-4*1*15

Δ=2304-60

Δ=2244

√Δ=2√561

y₁ = (- (-48) - 2√561) / (2*1)

y₁ = (48-2√561) / 2

y₁=24-√561

y₂ = (- (-48) + 2√561) / (2*1)

y₂ = (48+2√561) / 2

y₂=24+√561

x₁=48 - (24-√561)

x₁=48-24+√561

x₁=24+√561

x₂=48 - (24+√561)

x₂=48-24-√561

x₂=24-√561

24+√561 и 24-√561