Question

cineva va rog am mare nevoie

Answer 1

Răspuns:

19.

E(x) = 6x²-4x+9x-6-(x²+1-2x)-(4x²+1-4x)+26 =

= 6x²-4x+9x-6-x²-1+2x-4x²-1+4x+26 =

= x²+11x+18

E(7ⁿ-2) = (7ⁿ-2)²+11(7ⁿ-2)+18 =

= 7²ⁿ+4-4·7ⁿ+11·7ⁿ-22+18 =

= 7²ⁿ+7·7ⁿ =

= 7²ⁿ+7ⁿ⁺¹ =

= 7ⁿ⁺¹(7ⁿ⁻¹-1)

⇒ E(7ⁿ-2) - divizibil cu 7ⁿ⁺¹ (∀) n∈N*

21.

E(x) = 4x²+9+12x-(2²-x²)-5x²-12x =

= 4x²+9+12x-4+x²-5x²-12x =

= 5

E(x) = 5, (∀) x∈R

E(2020) = 5

⇒ E(x) = E(2020) = E(2021)