`11 / 9 - 4 / 13 - 18 / 26`
`= 11 / 9 - ( 4 / 13 + 18 / 26 )`
`= 11 / 9 - ( 8 / 26 + 18 / 26 )`
`= 11 / 9 - 26 / 26`
`= 11 / 9 - 1`
`= 11 / 9 - 9 / 9`
`= 2 / 9`
\(=\dfrac{11}{9}-\left(\dfrac{8}{26}+\dfrac{18}{26}\right)=\dfrac{11}{9}-\dfrac{26}{26}=\dfrac{11}{9}-\dfrac{9}{9}=\dfrac{2}{9}\)
