Question

cât face 2√7 x 2√7 ???

Answer 1

$2 \sqrt{7} \times 2 \sqrt{7} = 2 \times 2 \sqrt{7 \times 7} = 2 \times 2 \sqrt{49} = 2 \times 2 \times 7 = 28$

Answer 2

(2√7)²= 4*7=28

simplu.