Question

Ex 21,23. Dau coroana!

Answer 1

[tex]21.\text{Notam cu x lungimea traseului.}\\ \dfrac{x}{4}+\dfrac{1}{3}\left(x-\dfrac{x}{4}\right)+240=x\\ \dfrac{x}{4}+\dfrac{1}{\not3}\cdot \dfrac{\not3}{4}\cdot x+240=x\\ \dfrac{x}{4}+\dfrac{x}{4}+240=x\\ \dfrac{x}{2}+240=x|\cdot 2\\ x+480=2x\\ \boxed{x=480\ km}\\ \\ 22.\text{Notam cu x numarul de pagini.}\\ \dfrac{60}{100}\cdot x+\dfrac{1}{2}\cdot \dfrac{60}{100}\cdot x+60=x\\ \dfrac{3}{5}\cdot x+\dfrac{3}{10}\cdot x+60=x|\cdot 10\\ 6x+3x+600=10x\\ 9x+600=10x\\ \boxed{x=600\ pagini}[/tex]