Question

Ex 6 a si b va rooog!Dau coroană!Daca se poate si explicatie!!

Answer 1

a) le rationalizam pe toate
$\frac{12}{ \sqrt{7} }$
=
$\frac{12 \sqrt{7} }{7}$
$\frac{14}{2 \sqrt{7} } = \frac{14 \sqrt{7} }{2 \times 7} = \frac{14 \sqrt{7} }{14} = \frac{7 \sqrt{7} }{7}$
$\frac{13}{ \sqrt{7} } = \frac{13 \sqrt{7} }{7}$

$\frac{11}{ \sqrt{7} } = \frac{11 \sqrt{7} }{7}$
si acum au toate acelasi numitor si calculam
$\frac{12 \sqrt{7} + 7 \sqrt{7} + 13 \sqrt{7} - 11 \sqrt{7} } {7} = \frac{21 \sqrt{7} }{7} = 3 \sqrt{7}$
b) le rationalizam si le aducem la acelasi numitor
$\frac{7}{3 \sqrt{3} } = \frac{7 \sqrt{3} }{9} = \frac{14 \sqrt{3} }{18}$

$\frac{4}{2 \sqrt{3} } = \frac{4 \sqrt{3} }{6} = \frac{12 \sqrt{3} }{18}$
$\frac{5}{6 \sqrt{3} } = \frac{5 \sqrt{3} }{18}$
$\frac{4}{ \sqrt{3} } = \frac{4 \sqrt{3} }{3} = \frac{24 \sqrt{3} }{18}$
si le calculam
$\frac{14 \sqrt{3} - 5 \sqrt{3} + 12 \sqrt{3} - 24 \sqrt{3} }{18} = - \frac{3 \sqrt{3} }{18} = - \frac{ \sqrt{3} }{6}$