((3:\frac{9}{25}-15):3$\frac{1}{3}):0,5-\frac{2}{3} = ((\frac{3}{1}*\frac{25}{9}-15):\frac{10}{3}):\frac{1}{2}-\frac{2}{3} = ((\frac{25}{3}-\frac{45}{3})*\frac{3}{10})*2-\frac{2}{3} = (-\frac{20}{3}*\frac{3}{10})*2-\frac{2}{3} = -2*2-\frac{2}{3}= -4-\frac{2}{3} = -\frac{12}{3}-\frac{2}{3} = -\frac{14}{3}$
3% - -\frac{14}{3}
100% - x
x = \frac{-14/3*100}{3} = \frac{-1400/3}{3} = -\frac{1400}{3}*\frac{1}{3} = -\frac{1400}{9} = -155$\frac{5}{9}$