a) le rationalizam pe toate
[tex] \frac{12}{ \sqrt{7} } [/tex]
=
[tex] \frac{12 \sqrt{7} }{7} [/tex]
[tex] \frac{14}{2 \sqrt{7} } = \frac{14 \sqrt{7} }{2 \times 7} = \frac{14 \sqrt{7} }{14} = \frac{7 \sqrt{7} }{7} [/tex]
[tex] \frac{13}{ \sqrt{7} } = \frac{13 \sqrt{7} }{7} [/tex]
[tex] \frac{11}{ \sqrt{7} } = \frac{11 \sqrt{7} }{7} [/tex]
si acum au toate acelasi numitor si calculam
[tex] \frac{12 \sqrt{7} + 7 \sqrt{7} + 13 \sqrt{7} - 11 \sqrt{7} } {7} = \frac{21 \sqrt{7} }{7} = 3 \sqrt{7} [/tex]
b) le rationalizam si le aducem la acelasi numitor
[tex] \frac{7}{3 \sqrt{3} } = \frac{7 \sqrt{3} }{9} = \frac{14 \sqrt{3} }{18} [/tex]
[tex] \frac{4}{2 \sqrt{3} } = \frac{4 \sqrt{3} }{6} = \frac{12 \sqrt{3} }{18} [/tex]
[tex] \frac{5}{6 \sqrt{3} } = \frac{5 \sqrt{3} }{18} [/tex]
[tex] \frac{4}{ \sqrt{3} } = \frac{4 \sqrt{3} }{3} = \frac{24 \sqrt{3} }{18} [/tex]
si le calculam
[tex] \frac{14 \sqrt{3} - 5 \sqrt{3} + 12 \sqrt{3} - 24 \sqrt{3} }{18} = - \frac{3 \sqrt{3} }{18} = - \frac{ \sqrt{3} }{6} [/tex]
