If 1,5,35,7,5,5,1,λ,7 and 2λ,1,2 are coplanar , then the sum of all possible values of λ is

Let the given points be A,B,C,D respectively thenAB¯=OB¯-OA¯=6,0,-30BC¯=-6,λ-5,2CD¯=2λ-1,1-λ,-5since the above vectors are coplanar⇒ AB¯,BC¯,CD¯=0⇒60-30-6λ-522λ-11-λ-5=0 ⇒625−5λ+2λ−2−306λ−6−2λ2+11λ−5=010λ2−88λ+78=0Sum of the values of λ is λ=8810=445