One pound of Liquid malt extract would give you 36 points in one gallon of water. You would have a SG of 1.036 with one pound of LME in 1G of water.
Two cans of LME are 6.6 pounds. Since one pound = 36 points, you have 238 points.
In on gallon of water, this would be a 1.238 SG.
I dilute the 238 points in five gallons of water and the specific gravity is 1.048
If this fermented out to 1.010 FG, then you would have a 5% ABV beer.
I would definitely use both cans. Otherwise, you beer will have a SG of 1.024 which is way to low for every style out there.