Let be a polynomial that satisfies and for any real number Find the sum of all possible values of
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First we find the degree of p , assume that the degree is n so we can write : p ( x ) = k = 0 ∑ n a k x k a n = 0 , ∀ k ∈ { 0 , 1 … , n } , a k ∈ R Then the leading coefficient in ( x + 1 0 ) p ( 2 x ) is 2 n a n . And the leading coefficient in ( 8 x − 3 2 ) p ( x + 6 ) is 8 a n , then : 8 a n = 2 n a n ⟺ a n = 0 2 n = 8 ⟺ n = 3 . So p at most three real roots : set x = 4 to get ( 4 + 1 0 ) p ( 8 ) = 0 ⟹ p ( 8 ) = 0 set x = − 1 0 to get 0 = ( − 8 0 − 3 2 ) p ( − 4 ) ⟹ p ( − 4 ) = 0 set x = − 2 to get : ( − 2 + 1 0 ) p ( − 4 ) = ( − 1 6 − 3 2 ) p ( 4 ) ⟹ p ( 4 ) = 0 Then : p ( x ) = c ( x − 4 ) ( x + 4 ) ( x − 8 ) , and p ( 1 ) = 2 1 0 = 1 0 5 c then c = 2 , therefore p ( x ) = 2 ( x − 4 ) ( x + 4 ) ( x − 8 ) Easily : p ( 1 0 ) = 2 ⋅ 6 ⋅ 1 4 ⋅ 2 = 3 3 6