12 5/6*(4 7/11*3 6/7)=77/6*51/11*27/7=459/2 (40,425+4 3/8):2 4/5=(40,425+4,375):2,8=44,8:2,8=16 16-100% 459/2-х% х=459/2*100:16=1434,375%