x->numarul de m de stofa
(1/2)x->numarul de metri vanduti in prima zi
(2/5)x->numarul de metri de stofa vanduti in a treia zi
x-(1/2)x-(2/5)x=1233
aducem la acelasnumitor comun...adica 10
10x/10-5x/10-4x/10=1233
facem scaderile
x/10=1233
si trecem in cealalta parte cu semn schimbat
x=12330
(1/2)x=6165->in prima zi
(2/5)x=4932->in a doua zi
verificare:6165+4932+1233=12330