Olive oil is an EFA but not Omega 3/6 heavy like flax.

10% omega 6
15% saturated
1% omega 3
73% monounsaturated

To get the best of both worlds - use the Olive oil as a marinade for your meats to be cooked in and take the flax oil.

To better your world, eat fish at least 2 times a week to really get the "natural" Omega 3 & 6 fatty acids.

No matter if you take a flax oil or not, its always a good idea to cook with healthy fats.