x^4-y^4=15x^3y-xy^3=6,化为;xy(x^2-y^2)=6两式相除得：(x^2+y^2)/(xy)=5/2得：2x^2+2y^2=5xy(2x-y)(x-2y)=0得x=y/2,或x=2y当x=y/2,代入方程1得：y^4/16-y^4=15,得：y^4=-16,无解当x=2y,代入方程1得：16y^4-y^4=15,...