a: =7/9+2/3x9/4
=7/9+18/12
=7/9+3/2
=14/18+27/18=41/18
b: =3/8+7/5x10/3
=3/8+70/15
=3/8+14/3
=9/24+112/24=121/24
\(a,\dfrac{7}{9}+\dfrac{2}{3}.\dfrac{9}{4}=\dfrac{7}{9}+\dfrac{2.9}{3.4}=\dfrac{7}{9}+\dfrac{3}{2}=\dfrac{7.2+3.9}{18}=\dfrac{41}{18}\\ b,=\dfrac{3}{8}+\dfrac{7}{5}.\dfrac{10}{3}=\dfrac{3}{8}+\dfrac{7.10}{5.3}=\dfrac{3}{8}+\dfrac{14}{3}=\dfrac{3.3+14.8}{24}=\dfrac{121}{24}\)
`7/9 + 2/3 : 4/9`
`=7/9 + 2/3 xx 9/4`
`= 7/9 + (2xx9)/(3xx4)`
`= 7/9 + 3/2`
`= 14/19 + 27/18`
`= (14+27)/18`
`= 41/18`
`3/8 + 7/5 : 3/10`
`=3/8 + 7/5 xx 10/3`
`=3/8 + (7xx10)/(5xx3)`
`=3/8 + 14/3`
`=121/24`
