Răspunsuri

2014-03-11T00:21:21+02:00
Notam numarul total de pagini cu x . 
 \frac{3}{5} x +30 =  \frac{2}{3} x
 \frac{3}{5}x - \frac{2}{3}x= -30
Aducem la acelasi numitor .
 \frac{9x-10x}{15}=-30
-x=-30  · 15
-x=-450     ==> x=450 ==> cartea are 450 de pagini .