Connect Two sets of 5 meter RGB Lights
If both 5 meters strips came with one ac adapter each, you can connect the strips together, and put one ac at the start of the strip and the other ac adapter in the middle (where you connect the two strips together).

That amazon link shows:


LED voltage 12V
Wattage: 24W
Power Supply: AC/DC ADAPTOR INPUT 100-240V; OUTPUT 12V 3.0A 


the adapter gives you up to 3 amps, but each strip can use 2A, (24w / 12V = 2Amps)

The adapter can (and most of the time should) give you more amps than what you need, the strip will decide how much it will draw from the adapter, so amps won't burn the strip.

Or you could buy a single adapter that is 12v,  6 Amps (or higher, but has to be 12 v).

Hope this helps.