Question

me ajude , trabalho de prova !

Answer 1

a) $\sqrt{7}+ \sqrt{7}=2 \sqrt{7}$

b) $2 \sqrt{5}+7 \sqrt{5}-16 \sqrt{5}= (2+7-16) \sqrt{5}=-7 \sqrt{5}$

c) $4 \sqrt{125}+3 \sqrt{45}-30 \sqrt{5}= 4 \sqrt{5^2.5}+3 \sqrt{3^2.5}-30 \sqrt{5}=$
 = $20 \sqrt{5}+9 \sqrt{5}-30 \sqrt{5}=-1 \sqrt{5} = \sqrt{5}$

d) $\frac{ \sqrt{50}- \sqrt{18} }{ \sqrt{200} }= \frac{ \sqrt{2.5^2} - \sqrt{2.3^2} }{ \sqrt{2^3.5^2} }= \frac{5 \sqrt{2}-3 \sqrt{2} }{2.5 \sqrt{2} }= \frac{2 \sqrt{2} }{10 \sqrt{2} }= \frac{1}{5}$