Question

Simplificando a expressão: 3 (raiz quadrada de 2) - 2 (raiz quadrada de 18) + 3 (raiz quadrada de 72) , obtemos

Answer 1

$3\sqrt{2} -2\sqrt{18} + 3\sqrt{72}$

$3\sqrt{2} -2.3\sqrt{2} + 3.6\sqrt{2}\\ 3\sqrt{2} -6\sqrt{2} + 18\sqrt{2}= 15 \sqrt{2}$

Answer 2

$3 \sqrt{2}-2 \sqrt{18} +3 \sqrt{72}$
18|2 72|2
  9|3 36|2
  3|3 18|2
  1     9|3
         3|3
          1
18=2.3²
72=2.2².3²

$3 \sqrt{2} -2 \sqrt{2.3^2} +3 \sqrt{2.2^2.3^2} \\ 3 \sqrt{2} -2 .3\sqrt{2}+3.2.3 \sqrt{2} \\ 3 \sqrt{2} -6\sqrt{2}+18 \sqrt{2}\\ (3-6+18) \sqrt{2} \\ 15 \sqrt{2}$