Question

Ex. 2 și 3 !!!! Va rog !!! Dau coroana !!!

Answer 1

[tex]2. a)\\ \frac{2}{3}\ \textgreater \ \frac{n}{3}\\ Numitorii\ sunt\ la fel,\ deci\ se\ ignora\\ 2\ \textgreater \ n\\ n\ \textless \ 2,n\neq0\\ n=1\\\\ b)\\ \frac{5}{4}\ \textless \ \frac{5}{n}\\ Numaratorii\ sunt\ la\ fel,\ deci\ se\ ignora\ si\ se\ schimba\\\ semnul\\ 4\ \textgreater \ n\\ n\ \textless \ 4,n\neq0\\ n\in\{1;2;3\}[/tex]

$3.a)\\ Notam\ numarul\ penarelor\ cu\ p \\Notam\ numarul\ \ \ \ cartilor\ cu\ c\\\\ 2p+5c=95\\ 2p+3c=65\\ ------\ Scadem\ cele\ doua\ ecuatii\\ 2p+5c-(2p+3c)=95-65\\ 2p+5c-2p-3c=30 \\5c-3c=30\\ 2c=30\\ c=15\ (o\ carte\ costa\ 15\ lei)$

[tex]\\\\b)\\ Inlocuim\ in\ prima\ ecuatie\\ 2p+5c=95\\ 2p+5\cdot15=95\\ 2p+75=95\\ 2p=95-75\\ 2p=20\ (doua\ penare\ costa\ 20\ de\ lei)\\ 1p=10\\\\ c) \\4p+7c=\\ =4*10+7*15\\ =40+105\\ =145\\\\ Sper\ ca\ te-am\ ajutat! :)[/tex]