wxyz====a4+b4+c4+d4a2+b2+c2+d2ab+ac+ad+bc+bd+cdabcd
Let a,b,c and d be real numbers; and w,x,y and z some unknown constants such that they satisfy the system of equations above. State the following expression
(a+b+c+d)(a3+b3+c3+d3+abc+abd+bcd+acd)
in terms of w,x,y and z.