Question

Me ajuda aí por favor galera preciso para amanhã

Answer 1

Sejam as propriedades:

$a.\sqrt{x} +b.\sqrt{x} = (a+b)\sqrt{x}\\\\a.\sqrt{x} -b.\sqrt{x} = (a-b)\sqrt{x}$

Vamos lá

$\sqrt{7} +\sqrt{7} =(1+1)\sqrt{7}= 2\sqrt{7}\\\\\sqrt{10} +\sqrt{10} =(1+1)\sqrt{10}= 2\sqrt{10}\\\\9\sqrt{5} +\sqrt{5} =(9+1)\sqrt{5}= 10\sqrt{5}\\\\\\3\sqrt[5]{2} -8\sqrt[5]{2} =(3-8)\sqrt[5]{2} = -5\sqrt[5]{2} \\8\sqrt[3]{7} -13\sqrt[3]{7} =(8-13)\sqrt[3]{7} = -5\sqrt[3]{7} \\\\2\sqrt{4} -\sqrt{4} =(2-1)\sqrt{4}= 1\sqrt{4}$