Question

6 4/9+3 5/9
1-3/11
1- 13/ 40

Answer 1

$6 frac{4}{9} +3 frac{5}{9} =(6+3)+( frac{4}{9} + frac{5}{9} )=9+ frac{9}{9} =9+1=10 \ \ 1- frac{3}{11} = frac{11}{11} - frac{3}{11} = frac{8}{11} \ \ 1- frac{13}{40} = frac{40}{40} - frac{13}{40} = frac{27}{40}$