.i need help w this pls!!

For simplifying this fraction, let first consider it as
[tex]{:\implies \quad \sf \dfrac{x}{y}-1}[/tex]
If we take LCM, and simplify it further, we will be having ;
[tex]{:\implies \quad \sf \dfrac{x\cdot 1-1\cdot y}{y}}[/tex]
[tex]{:\implies \quad \boxed{\bf{\dfrac{x-y}{y}}}}[/tex]
This is the required answer