[tex]1\frac{3}{4} + \frac{2}{5} = 1\frac{15}{20} + \frac{8}{20} = 1\frac{23}{20}= 2\frac{3}{20}[/tex]
[tex]\frac{1}{5} + \frac{1}{3} = \frac{3}{15} + \frac{5}{15} = \frac{8}{15}[/tex]
[tex]1\frac{6}{11} +\frac{8}{11}= 1\frac{14}{11}= 2\frac{3}{11}[/tex]
[tex]\frac{3}{4} - \frac{2}{7}= \frac{21}{28} - \frac{8}{28} = \frac{13}{28}[/tex]
[tex]\frac{1}{2} *12 = \frac{12}{2} = 6[/tex]