Q30 If a, b, c are all different and
a a3 a4-1 b b3 b4-1 c c3 c4-1
=0
, prove that abc(ab+bc+ca)=a+b+c
Solution
,
,
a | a3 | a4-1 |
b | b3 | b4-1 |
c | c3 | c4-1 |