Question

Соч по математике за 2 четверть СРОЧНООООО 5 класс​

Answer 1

Ответ:

4. $4\frac{11}{13}$

5. $4\frac{11}{15}m$

6. $16\frac{2}{15}$

Пошаговое объяснение:

4. $(12\frac{5}{13}+x) -9\frac{9}{13}=7\frac{7}{13}\\12\frac{5}{13}+x=7\frac{7}{13}+9\frac{9}{13}\\x=7\frac{7}{13}+9\frac{9}{13}-12\frac{5}{13}\\x= (7+9-12)+\frac{7+9-5}{13}\\x=4+\frac{11}{13}\\x=4\frac{11}{13}$

5. Стороны треугольника

$a=\frac{1}{5} m, b=1\frac{5}{6} m, c=2\frac{7}{10} m$

Тогда периметр P равен:

$P=a+b+c=\frac{1}{5} m+1\frac{5}{6} m+2\frac{7}{10} m=(1+2+\frac{6}{30} +\frac{25}{30}+\frac{21}{30})m=\\=(3+\frac{6+25+21}{30})m= 3\frac{52}{30}m=4\frac{22}{30}m=4\frac{11}{15}m$

6. $(7-\frac{2}{3}) : (1\frac{3}{4} -\frac{1}{6})* (1\frac{1}{5}+2\frac{2}{3}+\frac{1}{6})=(6\frac{3}{3}-\frac{2}{3}) : (1\frac{9}{12} -\frac{2}{12})* (1\frac{6}{30}+2\frac{20}{30}+\frac{5}{30})=\\=(6\frac{3-2}{3}) : (1\frac{9-2}{12} )* (3\frac{6+20+5}{30})=6\frac{1}{3} : 1\frac{7}{12} * 3\frac{31}{30}=\frac{19}{3} : \frac{19}{12} * \frac{121}{30}=\\=\frac{19}{3} * \frac{12}{19} * \frac{121}{30}=\frac{1}{1} * \frac{4}{1} * \frac{121}{30}=\frac{2}{1} * \frac{121}{15}=\frac{242}{15}=16\frac{2}{15}$