`5/13 xx 2/7 +12/7 xx 5/13 - 5/13`
`= 5/13 xx 2/7 +12/7 xx 5/13 - 5/13xx1`
`= 5/13 xx (2/7 + 12/7 - 1)`
`= 5/13 xx ( 14/7 -1 )`
`= 5/13 xx ( 2-1)`
`= 5/13 xx 1`
`= 5/13`
\(\dfrac{5}{13}x\dfrac{2}{7}+\dfrac{12}{7}x\dfrac{5}{13}-\dfrac{5}{13}=\dfrac{5}{3}x\left(\dfrac{2}{7}+\dfrac{12}{7}-1\right)=\dfrac{5}{3}x\left(2-1\right)=\dfrac{5}{3}\)