Question

dau coronita, mulțumesc anticipat ​

Answer 1

 

$\displaystyle\bf\\\\Folosim~formula:\\\\(a-b)(a+b)=a^2-b^2\\\\Rezolvare:\\\\(2\sqrt{3}-\sqrt{5})(2\sqrt{3}+\sqrt{5})=\Big(2\sqrt{3}\Big)^2-\Big(\sqrt{5}\Big)^2 =4\times3-5=12-5=\boxed{\bf7\in N}$

 

 

Answer 2

Răspuns:

- 13

Explicație pas cu pas:

(2√3 - √5)(2√3 + √5) =

4 × 3 - 25 =

12 - 25 =

- 13

• Formula folosita

(a - b)(a + b) = a² - b²