a: =9/11(7/4+5/4)=9/11x3=27/11
b: \(=\dfrac{28}{5}\cdot\dfrac{5}{8}\cdot\dfrac{5}{4}=\dfrac{28}{8}\cdot\dfrac{5}{4}=\dfrac{140}{32}=\dfrac{35}{8}\)
c: \(=\dfrac{2}{6}+\dfrac{4}{5}\cdot\dfrac{6}{5}-\dfrac{2}{5}=\dfrac{67}{75}\)
a,=(7/4+5/4):11/9
=3:11/9
=27/11
b,=28/5.5/4.5/8
=7.5/8
=35/8
c,=1/3+24/25-2/5
=97/75-2/5
=67/75
7/4:11/9+5/4:11/9
=7/4×9/11+5/4×9/11
=9/11×(7/4+5/4)
=9/11×12/4
=9/11×3
=27/11
b)
28/5:4/5×5/8
=28/5×5/4×5/8
=28/4×5/8
=7×5/8
=35/8
c)
2/3×3/6+4/5:5/6−2/5
=2/6+4/5×6/5−2/5
=1/3+24/25−2/5
=(24/25−2/5)+1/3
=14/25+1/3
=67/75
`a)7/4:11/9+5/4:11/9`
`=7/4×9/11+5/4×9/11`
`=9/11×(7/4+5/4)`
`=9/11×12/4`
`=9/11×3`
`=27/11`
`b)28/5:4/5×5/8`
`=28/5×5/4×5/8`
`=28/4×5/8`
`=7×5/8`
`=35/8`
`c)2/3×3/6+4/5:5/6−2/5`
`=2/6+4/5×6/5−2/5`
`=1/3+24/25−2/5`
`=(24/25−2/5)+1/3`
`=14/25+1/3`
`=67/75`