If $$\frac{{xy}}{{x + y}} = a,$$$$\frac{{xz}}{{x + z}} = b$$and $$\frac{{yz}}{{y + z}} = c{\text{,}}$$where a, b, c are all non - zero numbers, then x equals to?

• A. $\frac{{2abc}}{{ab + bc - ac}}$$
• B. $\frac{{2abc}}{{ab - bc + ac}}$$
• C. $\frac{{2abc}}{{bc + ac - ab}}$$
• D. $\frac{{2abc}}{{ab + bc + ac}}$$