The expression is
.
To subtract
means add
.

To add fractions the denominators must be equal.
\Find the least common denominator (LCD).
\Multiples of 10: 10,20,30,40,.............
\Multiples of 5: 5,10,15,20,25,............
\The least common multiple of 5 and 10 is 10.
\Rewrite each fraction with a common denominator of 10.
\

Rewrite the equivalent fractions using the LCD.
\
= 
Denominators are same, write sum of numerators over denominator.
\
(Lcm is 10)
(Add:
)
The difference is
.