[latex]1) \ frac{2}{5} + frac{1}{4} = frac{8+5}{20} = frac{13}{20} \ 2) \ frac{4}{7} + frac{2}{3} = frac{12+14}{21} = frac{26}{21} =1 frac{5}{21} \ 3) \ frac{3}{11} + frac{1}{2} = frac{6+11}{22} = frac{17}{22} \ 4) \ frac{2}{5}+ frac{3}{8} = frac{16+15}{40} = frac{31}{40} \ 5) \ frac{3}{7} + frac{4}{5} = frac{15+28}{35} = frac{43}{35} =1 frac{8}{35} \ 6) \ frac{2}{9} + frac{1}{5} = frac{10+9}{45} = frac{19}{45} [/latex]