We need that the 100 has a 2 in the denominator. To do this, we can multiply on top and bottom by 2:
[tex]100\cdot\frac{2}{2}=\frac{200}{2}[/tex]Now, we can make the subtraction:
[tex]\frac{200}{2}-\frac{1}{2}=\frac{199}{2}[/tex]The answer is 199/2