Which expression represents 'the product of xxx and yyy, divided by their sum'?
fracxyx+y\\frac{xy}{x+y}fracxyx+y
xy(x+y)xy(x+y)xy(x+y)
fracx+yxy\\frac{x+y}{xy}fracx+yxy
fracxy+y\\frac{x}{y}+yfracxy+y