Final answer:
To simplify the complex fraction, multiply the numerators together and multiply the denominators together. Combine like terms in the denominator to further simplify the expression.
Step-by-step explanation:
To simplify the complex fraction, you can create a common denominator by multiplying x and y. The expression then becomes 7(xy) / (y + x). Multiplying the numerators together gives 7xy, while multiplying the denominators gives yx + xy. Combining like terms in the denominator gives 2xy, so the simplified complex fraction is 7xy / 2xy.