[tex] \frac{1}{3}x-5 = suna cheltuita pe alimente [/tex]
[tex] \frac{2}{5}[x- (\frac{1}{3}x+5)] = suma cheltuita pe tricou [/tex]
[tex]x-[ \frac{2}{5}(x- \frac{1}{3}x+5)]=39 [/tex]
[tex]x- \frac{2}{5}x+ \frac{2}{15}x-2=39 [/tex]
[tex] \frac{15x-6x+2x}{15}-2=39 [/tex]
[tex] \frac{11x}{15} =41[/tex]
11x=41*15
x=[tex] \frac{41*15}{11} =55.9lei[/tex]