Question

Qual o valor da expressão
y=|√5-2|-|2-√5| ?

Answer 1

$y=\left|\sqrt{5}-2\right|-\left|2-\sqrt{5}\right|\\\\\mathrm{Aplicar\:as\:propriedades\:dos\:valores\:absolutos}:\quad \left|A\right|=A\:,\:A\:\ge \:0\\\\\left|\sqrt{5}-2\right|=\sqrt{5}-2\\\\y=\sqrt{5}-2-\left|2-\sqrt{5}\right|\\\\\mathrm{Aplicar\:as\:propriedades\:dos\:valores\:absolutos}:\quad \left|A\right|=-A\:,\:A<0\\\\\left|2-\sqrt{5}\right|=-2+\sqrt{5}\\\\y=\sqrt{5}-2-\left(\sqrt{5}-2\right)\\Apos, simplifique\\Obteremos.\\y=0$