Question

1. Aratati ca numarul n= (√5 + 2)² + ( √5 - 1 ) ( √5 +1)- ( 4√5 + 3) este numar intreg.

2. Fie expresia E(x)=( 2x-1)² - 2(2x-1)(x+1)+(x+1)²
a) Aduceti expresia la o forma mai simpla
b) Calculati E(0)

Answer 1

n= 5+4$\sqrt{5}$  +4+5+$\sqrt{5}$-$\sqrt{5}$-5-1 -4$\sqrt{5}$-3=5+4+5-1-3=10