Se considera numarul a=| radical7-5radical7|:(-radical28).Aratati ca a£Z​

Răspuns :

[tex] \sqrt{7} < 5 \sqrt{7} \\ \sqrt{7} < \sqrt{7 \times {5}^{2} } \\ a =( 5 \sqrt{7} - \sqrt{7} ) \div ( - 2 \sqrt{7} ) \\ a = 4 \sqrt{7} \div ( - 2 \sqrt{7}) \\ a = - 2 \sqrt{1} \\ a = - 2 \: = > [/tex]

a€Z