Assuming that the left side is a determinant, and expanding it by the first column, we get
=(b2+c2)[(c2+a2)(a2+b2) - (bc)2] - ab[ab(a2+b2) - ac(bc)] +ac[ab(bc) - ac(c2+a2)]
which I ask you to multiply out, carefully, to finish the job. It's easier to do on paper than to type in!
YOU CAN DO IT!