Question

va rog sa ma ajutati si sa imi scrieti explicit . dau 30 puncte

Answer 1

La a Se scot factorii de sub radical si apoi se rationalizeaza numitorii:
$\sqrt{8}=2 \sqrt{2}$
$\sqrt{18}=3 \sqrt{2}$
$\sqrt{32}=4 \sqrt{2}$
$a= \frac{1}{ \sqrt2 } + \frac{2}{2\sqrt2}+ \frac{3}{3\sqrt2}+ \frac{4}{4\sqrt2}$
Se simplifica fractiile
Se obtine
$a= \frac{1}{ \sqrt2 } + \frac{1}{\sqrt2}+ \frac{1}{1\sqrt2}+ \frac{1}{1\sqrt2}$
$a= 4\frac{1}{ \sqrt2 }$
Rationalizam amplificand cu √2.
a=4√2/2
a=2√2

b) facem calculele de sub radicali.
La numarator: $\sqrt{13^2-5^2}= \sqrt{169-25}= \sqrt{44} =2 \sqrt{11}$
La numitor: $\sqrt{10^2-8^2}= \sqrt{100-64}= \sqrt{36} =6$
Deci b=$\frac{2 \sqrt{11}} {6}= \frac{ \sqrt{11} }{3}$
(dupa ce am simplificat fractia cu 2)