Uprość (ułamki, pierwiastki).

[janinka65]

Zapisz w jak najprostszej postaci:

a. \(\displaystyle{ \frac{1}{4}\sqrt{7}-\frac{2}{3}\sqrt{7}=}\)

b. \(\displaystyle{ 2\sqrt{5} : 15 +3 \sqrt{5}: 10 =}\)

[Revius]

a.
\(\displaystyle{ \frac{1}{4} \sqrt{7} - \frac{2}{3}\sqrt{7} = \frac{3}{12} \sqrt{7} - \frac{8}{12}\sqrt{7} = - \frac{5}{12}\sqrt{7}}\)


b.
\(\displaystyle{ 2\sqrt{5} : 15 +3 \sqrt{5} : 10 = \frac{2}{15}\sqrt{5} + \frac{3}{10}\sqrt{5}= \frac{4}{30}\sqrt{5} + \frac{9}{30}\sqrt{5} = \frac{13}{30}\sqrt{5}}\)

[raphel]

a) \(\displaystyle{ ... = - \frac{5}{12} \sqrt{7}}\)
b) \(\displaystyle{ \frac{2 \sqrt{5} }{15} + \frac{3 \sqrt{5} }{10} = \frac{4 \sqrt{5} + 9 \sqrt{5} }{30} = \frac{13 \sqrt{5} }{30}}\)