Question

conta explicativa

√2· (√126 +√56) - √3 ( √84 - √3 +√48 )

Answer 1

Vamos pensar assim:

$\sqrt{4}-\sqrt{9} = 2-3 = -1\\e \sqrt{4-9} \sqrt{5}$

somando direto nao da!

mas se fossem raises de mesma base

tire o mmc dos numero nas raizes

126  = 2.3.3.7

56 = 2.2.2.7

84  = 2.2.3.7

48 = 2.2.2.2.3

podemos reescrever

$\sqrt{2}  (\sqrt{2.3^2.7} +\sqrt{2^2.2.7})-\sqrt{3}  (\sqrt{2^2.3.7} -\sqrt{3} +\sqrt{2^2.2^2.3} )\\\\\sqrt{2} (3\sqrt{2.7} +2\sqrt{2.7})-\sqrt{3}  (2\sqrt{3.7} -\sqrt{3} +4\sqrt{3} )\\\\\sqrt{2} (5\sqrt{2.7} )-\sqrt{3}  (2\sqrt{3.7} +3\sqrt{3} )\\\\(5\sqrt{2.2.7} )- (2\sqrt{3.3.7} -3\sqrt{3.3} )\\\\5.2\sqrt{.7}- 2.3\sqrt{7} -3.3\\\\10\sqrt{.7}- 6\sqrt{7} -9\\\\4\sqrt{.7} -9$

bons estudo