\(\dfrac{3}{4}=\dfrac{1}{3}\times\left(a-\dfrac{2}{5}\right):\dfrac{7}{5}\)
\(\left(a-\dfrac{2}{5}\right):\dfrac{7}{5}=\dfrac{3}{4}:\dfrac{1}{3}\)
\(\left(a-\dfrac{2}{5}\right):\dfrac{7}{5}=\dfrac{9}{4}\)
\(\left(a-\dfrac{2}{5}\right)=\dfrac{9}{4}\times\dfrac{7}{5}\)
\(a-\dfrac{2}{5}=\dfrac{63}{20}\)
\(a=\dfrac{63}{20}+\dfrac{2}{5}\)
\(a=\dfrac{71}{20}\)
`3/4 =1/3xx ( a- 2/5): 7/5`
`=> 1/3xx ( a- 2/5): 7/5 =3/4`
`=> ( a- 2/5): 7/5 =3/4:1/3`
`=> ( a- 2/5): 7/5 =3/4 xx3`
`=>( a- 2/5): 7/5 =9/4`
`=>a- 2/5=9/4xx7/5`
`=>a- 2/5=63/20`
`=>a=63/20+2/5`
`=>a=63/20+8/20`
`=>a=71/20`
\(\dfrac{1}{3}x\left(a-\dfrac{2}{5}\right):\dfrac{7}{5}=\dfrac{3}{4}\\ \dfrac{1}{3}x\left(a-\dfrac{2}{5}\right)=\dfrac{3}{4}x\dfrac{7}{5}\\ \dfrac{1}{3}x\left(a-\dfrac{2}{5}\right)=\dfrac{21}{20}\\ \left(a-\dfrac{2}{5}\right)=\dfrac{21}{20}:\dfrac{1}{3}\\ a-\dfrac{2}{5}=\dfrac{63}{20}\\ a=\dfrac{63}{20}+\dfrac{2}{5}\\ a=\dfrac{71}{20}\)