Your posting says "Solve." You can't "Solve" something that doesn't have an equality or inequality relationship established. There is no equals sign, nor is there any sort of inequality sign. The only thing that you can do in terms of solving this is to state the set of values for which this entire expression is defined.
Since the denominator of the third fraction is simply the product of the other two denominators, that is to say:
We only need to examine the values for which the first and second fractions would be undefined.
and
Meaning that the entire expression is undefined for x = 3 or x = -4. So we can say that:
is defined for
On the other hand, if you were simply being careless with your use of language and you really meant "Simplify" then that is another story altogether.
Remember that:
So
is the Common Denominator and:
John