No, your motherboard only has space for one PCI-E X16 (The bus that 95% of Gfx cards use), which is already in use by your existing GTX 550 Ti

For 2 video cards you need 2 pci express x16 slots that look like this |=====|=======================|, not this |=========================|=====|. The latter is regular pci not for video cards.

in basic terms take a verify out the cardboard and observe what quantity outputs it has. it might have a DVI, a VGA, and an HDMI, or actual a DVI and VGA, or 2 VGA's or a HDMI and a DVI or quite any mixture between them...

Yes you can