Question 62637
Let me know if I misunderstand your problem, sometimes with fractions, it's hard to know when denominators begin and end without parentheses.
{{{2ab^1+4a^2y^(-1)/a-7x^(-1)y/y^(-2)}}}
{{{2ab+4a^(2-1)/y^1-7y^(1+2)/x^1}}}
{{{2ab+4a/y-7y^3/x}}}
There are no like terms if I am reading this correctly.
The best we can do is give it a common denominator if you need it combined:
{{{2abxy/xy+4ax/xy-7y^4/xy}}}
{{{(2abxy+4ax-7y^4)/xy}}}
Happy Calculating!!!