Answer:
Step-by-step explanation:
xa+yb=c
xb+yc=a
xc+ya=b
add
x(a+b+c)+y(a+b+c)=a+b+c
x+y=1 ... (1)
xac+ybc=c²
xab+yac=a²
xbc+yab=b²
add
x(ab+bc+ca)+y(ab+bc+ca)=a²+b²+c²
[tex]x+y=\frac{a^2+b^2+c^2}{ab+bc+ca} \\\frac{a^2+b^2+c^2}{ab+bc+ca} =1\\a^2+b^2+c^2=ab+bc+ca\\a^2+b^2+c^2-ab-bc-ca=0\\a^3+b^3+c^3-3abc=(a+b+c)(a^2+b^2+c^2-ab-bc-ca)=(a+b+c)(0)=0\\a^3+b^3+c^3=3abc\\\frac{a^3}{abc} +\frac{b^3}{abc} +\frac{c^3}{abc} =3\\\frac{a^2}{bc} +\frac{b^2}{ca} +\frac{c^2}{ab} =3[/tex]