Question

If a+b+2c=0 prove that a cube + b cube + 8c cube = 6ab

Answer 1

cubing both sides

$(a + b + 2c) {}^{3} = {a}^{3} + {b}^{3} + 8 {c}^{3} + 2ab + 4bc + 4ac = 0$

we can see that it is not posdible to get given equation