Помогите пожалуйста x*x+y*y=10 xy=3 это система

$\left \{ {{ x^{2} + y^{2}=10 } \atop {xy=3}} \right. \\ \left \{ {{ x^{2} + y^{2}=10 } \atop {x= \frac{3}{y} }} \right. \\ ( \frac{3}{y} )^{2} + y^{2} =10 \\ \frac{9}{ y^{2} } + y^{2} =10 \\ \frac{9+ y^{4} }{y ^{2} } = \frac{10 y^{2} }{ y^{2} } \\ 9+ y^{4}-10 y^{2} =0 \\ y^{2} =a \\ a ^{2} -10a+9=0 \\ D=10 ^{2} -4*9*1=64 \\ a_{1} = \frac{10-8}{2} =1 \\ a_{2} = \frac{10+8}{2} =9 \\ y^{2} =1 \\ y_{1} =1 \\ y_{2} =-1 \\ y^{2} =9 \\ y_{3} =3 \\ y_{4} =-3$ $\\ x_{1} =3 \\ x_{2} =-3 \\ x_{3} =1 \\ x_{4=-1}$