Am nevoie urgent! Mulțumesc anticipat!

Răspuns:
Explicație pas cu pas:
E(x) = (x - 1)*x*(x + 1) - x*(x^2 - 2)
= (x^2 - 1)*x - x^3 + 2x = x^3 - x - x^3 + 2x = x
_________
E(x) = x
E(2p - 3) = 2p - 3
I2p - 3I ≤ 2
-2 ≤ 2p - 3 ≤ 2
1 ≤ 2p ≤5
1/2 ≤ p ≤ 5/2
p ∈ {1; 2}
1 + 2 = 3