Question

x^2+y^2=20 x^2-5xy+6y^2=0

Answer 1

x^2-5xy+6y^2=0

(x-2y)(x-3y)=0

x=2y或者x=3y

当x=2y时,4y^2+y^2=20 y=2或-2 则x=4或-4

当x=3y时,9y^2+y^2=20 y=+ -根号2 则x=+ -3根号2