Question

simplificando a expressao 3 raiz de 2 -2raiz de 18 +3 raiz de 72 obtem ?
a) 3 rais de 2
b) 24 rais de 2
c) 15 rais de 2
d) -15 rais de 2
PRECISO URGENTE DESSA CONTA PFV ME AJUDEM

Answer 1

$\ \ \ 3 \sqrt{2} -2 \sqrt{18} +3 \sqrt{72}\\ \\=3 \sqrt{2} -2 \sqrt{9\cdot2} +3 \sqrt{36\cdot2}\\ \\=3 \sqrt{2} -2 \cdot\sqrt{9}\cdot\sqrt{2} +3 \cdot\sqrt{36}\cdot\sqrt{2}\\ \\=3 \sqrt{2} -2 \cdot3\cdot\sqrt{2} +3 \cdot6\cdot\sqrt{2}\\ \\=3 \sqrt{2} -6\sqrt{2} +18\sqrt{2}\\ \\=15\sqrt{2}$