Question

rationalizarea numitorului:
$\frac{15}{2 \sqrt{18} } =?$
$\frac{20}{7 \sqrt{300} } =$$- \frac{18}{5 \sqrt{72} } =$
[tex] \frac{ \sqrt{10} }{3 \sqrt{5} } =
[/tex]
$\frac{2 \sqrt{21} }{3 \sqrt{14} } =$
$\frac{3}{ \sqrt{3} } =$
$-\frac{5 \sqrt{6} }{2 \sqrt{5} } =$
$\frac{7 \sqrt{6} }{3 \sqrt{14} } =$

Answer 1

15/2√18=(15·2√18)/(2√18·2√18)=30√18/4·18=(30·3√2)/72=90√2/70 =9√2/7
20/7√300=(20·7√300)/(7√300·7√300)=140√300/49·300=(140·10√3)/49·300 simplif=
=14√3/49·3=14/√3/147 simplif cu 7=2√3/21
acum fac direct
18/5√72=(18·5√72)/25·72=simplif=√72/20=6√2/20=3√2/10
√10/3√5=(√10·3√5)/9·5=simplif=√50/15=5√2/15=√2/3
2√21/3√14=(2√21·3√14)/9·14=simplif=√294/21=7√6/21=√6/3
3/√3=3√3/3=√3
-5√6/2√5=(-1)(5·2√6√5)/4·5=-√30/2
7√6/3√14=(7√6·3√14)/9·14=√84/6=4√21/6=2√21/3