Question

Vă rog ajutati-mă!
Aveti poza mai sus. Imi trebuie doar ce este incercuit.

Answer 1

a)
1/2+1,(2)=1/2+(12-1)/9=1/2+11/9=(9+22)/18=31/18=1,7(2)

2a
A=[3/(2√3-√5)-1/(√5-√3)-2(3√3+2√5)]:(√5-√3)=
=[3(2√3+√5)/(2√3-√5)(2√3+√5)-1(√5+√3)/(√5-√3)(√5+√3)-
-2(3√3-2√5)/(3√3+2√5)(3√3-2√5)]:(√5-√3)=
=[3(2√3+√5)/(12-5)-(√5+√3)/(5-3)-2(3√3-2√5)/(27-20)]:(√5-√3)=
=[3(2√3+√5)/7-(√5+√3)/2-2(3√3-2√5)/7]:(√5-√3)=
=(6√3+3√5)/7-(√5+√3)/2-(6√3-4√5)/7]:(√5-√3)=
=[(6√3+3√5-6√3+4√5)/7-(√5+√3)/2]:(√5-√3)=
=[7√5/7-(√5+√3)/2]:(√5-√3)=
=[√5-(√5+√3)/2]:(√5-√3)=
=[(2√5-√5-√3)/2]:(√5-√3)=
=(√5-√3)/2(√5-√3)=
=(√5-√3)(√5+√3)/2(√5-√3)(√5+√3)=
=(5-3)/2(5-3)=1/2=0,5

2b
(A+1/2)²⁰¹²+(A+1/2)⁻²⁰¹¹=(1/2+1/2)²⁰¹²+(1/2+1/2)⁻²⁰¹¹=1²⁰¹²+1⁻²⁰¹¹=1+1=2