\(8\dfrac{2}{5}=\dfrac{42}{5}\)
\(5\dfrac{3}{4}=\dfrac{23}{4}\)
\(4\dfrac{3}{7}=\dfrac{31}{7}\)
\(2\dfrac{1}{10}=\dfrac{21}{10}\)
`8 2/5=( (8xx5)+2 )/5=(40+2)/5=42/5`
`5 3/4=( (5xx4)+3 )/4=(20+3)/4=23/4`
`4 3/7=( (4xx7) + 3)/7=(28+3)/7=31/7`
`2 1/10=( (2xx10)+1)/10=(20+1)/10=21/10`