[tex] x^{2} [/tex]/у+у2/х=18,
х+у=12

x+y=12   y=12-xx²/y+y²/x=18   (x³+y³)/xy=18  (x+y)(x²-xy+y²)=18xy 12*(x²+2xy-3xy+y²)=18xy   |÷62((x²+2xy+y²)-3xy)=3xy2((x+y)²-3xy)=3xy2(12²-3xy)=3xy288-6xy=3xy9xy=288xy=32     x(12-x)=3212x-x²=32x²-12x+32=0   D=16x₁=4    y₁=8x₂=8    y₂=4.