[tex]x + \frac{x}{2} + \frac{x}{4} = 35 \\ \\ \frac{x}{1} + \frac{x}{2} + \frac{x}{4} = 35 \\ \\ \frac{4x}{4} + \frac{2x}{4} + \frac{x}{4} = 35 \\ \\ \frac{4x+2x+x}{4} = 35 \\ \\ 4x+2x+x =35*4 \\ 7x = 140 \\ \\ x= \frac{140}{7} =20 \\ \\ \text{Proba: } \\ 20 + 10 + 5 = 35[/tex]