Найди значение выражения : 1)1/9+ 4/9; 2) 7/8-3/8; 3) 15/19-6/19 4) 5/16 +2/16; 5)3/14 +11 /14; 6)11 /21+4/21.

1) [tex]\frac{1}{9}+\frac{4}{9}=\frac{5}{9}[/tex]
2) [tex]\frac{7}{8}-\frac{3}{8}=\frac{4}{8}=\frac{1}{2}=0,5[/tex]
3) [tex]\frac{15}{19}-\frac{6}{19}=\frac{9}{19}[/tex]
4) [tex]\frac{5}{16}+\frac{2}{16}=\frac{7}{16}=0,4375[/tex]
5) [tex]\frac{3}{14}+\frac{11}{14}=\frac{14}{14}=1[/tex]
6) [tex]\frac{11}{21}+\frac{4}{21}=\frac{15}{21}=\frac{5}{7}[/tex]

[tex] 1)\frac{1}{9} + \frac{4}{9} = \frac{1+4}{9} = \frac{5}{9} \\ \\ 2) \frac{7}{8}- \frac{3}{8} = = \frac{7-3}{8} = \frac{4}{8} \\ \\ 3) \frac{15}{19} - \frac{6}{19} = \frac{15-6}{19} = \frac{9}{19} \\ \\ 4) \frac{5}{16} + \frac{2}{16} = \frac{5+2}{16} = \frac{7}{16} \\ \\ 5) \frac{3}{14} + \frac{11}{14} = \frac{3+11}{14} = \frac{14}{14}=1 \\ \\ 6) \frac{11}{21} + \frac{4}{21} = \frac{11+4}{21} = \frac{15}{21} [/tex]