Notez cu x numarul total de pagini.
In prima zi : [tex] \frac{x}{3} [/tex] , raman [tex] \frac{2x}{3} [/tex]
A doua zi : [tex]2 * \frac{2x}{3*3} = \frac{4x}{9} [/tex] , raman [tex] \frac{5x}{9} =12[/tex]
[tex]x - \frac{x}{3} - \frac{4x}{9} = 12[/tex]
Aducem la acelasi numitor, respectiv 9.
[tex]9x-3x-4x = 9 * 12[/tex]
2x = 108 => x=54 (pagini in total)
Verificare :
[tex] \frac{54}{3} =18[/tex] ( citite in prima zi, raman 54 - 18 = 36 )
[tex] \frac{2*36}{3} = 2 * 12 =24[/tex] ( citite in a doua zi, raman 36 - 24 = 12 pentru a treia zi )
Se verifica.
