Question

if a+b+c=5 and ab+ bc+ ca=10 then prove that a^3+b^3+c^3-3and=-25

Answer 1

a=5-b-c
b=5-c-a
c=5-a-b
a+b= 5-c
a+c=5-b
b+c=5-a


a^3+b^3+c^3-3=
=(5-b-c)^ 3+(5-c-a)^3+(5-a-c)^3-3
=