What is the common denominator of y+y-3/3 in the complex fraction y+y-3/3/5/9+2/3y

This is the concept of algebra, the denominator of y+(y-3)/3  will be as follows;
the expression y+(y-3)/3 can be written as:
y/1+(y-3)/3
the denominator of the first term is 1 and that of the second denominator is 3, to get the common denominator for both terms we multiply both denominators;
thus the common denominator will be:
3*1=3
thus the our common denominator will be 3: