Step-by-step explanation:
Mohammed used 3 1/2 ink cartridges = [tex]\dfrac{7}{2}[/tex]
Luigi used 1 3/4 ink cartridges = [tex]\dfrac{7}{3}[/tex]
It means that Mohammed used more ink cartridges than Luigi. The more amount is calculated as follows :
[tex]\dfrac{7}{2}-\dfrac{7}{3}=\dfrac{7\times3-7\times 2}{6}\\\\=\dfrac{21-14}{6}\\\\=\dfrac{7}{6}[/tex]
So, [tex]\dfrac{7}{6}[/tex] more ink cartridges Mohammed used than Luigi.
