Сначала в скобках: 3511+1811=4+1311=52113\frac{5}{11}+1\frac{8}{11}=4+\frac{13}{11}=5\frac{2}{11}3115+1118=4+1113=5112. Далее: 10−5211+4211=4911+4211=8+1111=910-5\frac{2}{11}+4\frac{2}{11}=4\frac{9}{11}+4\frac{2}{11}=8+\frac{11}{11}=910−5112+4112=4119+4112=8+1111=9. Ответ: 999.
3511+1811=4+1311=52113\frac{5}{11}+1\frac{8}{11}=4+\frac{13}{11}=5\frac{2}{11}3115 +1118 =4+1113 =5112 .
Далее:
10−5211+4211=4911+4211=8+1111=910-5\frac{2}{11}+4\frac{2}{11}=4\frac{9}{11}+4\frac{2}{11}=8+\frac{11}{11}=910−5112 +4112 =4119 +4112 =8+1111 =9.
Ответ: 999.