Write the mixed numbers as an improper fraction. 
Rewrite the expression
\
To subtract fractions the denominators must be equal.
\Find the least common denominator (LCD).
\Write the prime factorization of each denominator.
\
Multiply the highest power of each factor in either number.
\
LCD of the fractions is 54.
Rewrite the equivalent fractions using the LCD.
\

Rewrite the expression using the LCD.
\
As denominators are same, write difference of numerators over denominator. 
Subtract the numerators.
\
Divide out common factor.
\
The difference is
.