Question

( 2 radical din3 - 1 )la patrat=?
(radical din3 + 2 )la patrat =?
Chiar am nevoie de ajutor, as fi foarte multumita daca m-ati ajuta. :)

Answer 1

$La~prima~folosim~identitatea~(a-b) ^{2} = a^{2} -2ab+b^{2},~iar~la~a~ \\ doua,~identitatea~(a+b)^{2}=a^{2}+2ab+b^{2}. \\ \\ a)~(2 \sqrt{3} -1)^{2}=(2 \sqrt{3})^{2}-2*2 \sqrt{3}*1+1^{2}= 12-4 \sqrt{3}+1= \\ =13-4 \sqrt{3}. \\ \\ b)~( \sqrt{3}+2)^{2}= (\sqrt{3})^2+ 2* \sqrt{3}*2+2^2 = 3+4 \sqrt{3}+4=7+4 \sqrt{3} .$

Answer 2

la prima: 12-4 $\sqrt{3}$ +1=13-4$\sqrt{3}$
la a doua : 3+4$\sqrt{3}$ +4=7+4$\sqrt{3}$