Yes you can use that power supply without any problem.
But IMO, as BlacksunKing said, cx series arent very reliable, even if that psu handle that system, id recommend you to get a better brand. I myself own a XFX 550w that already handled a R9 280X and right now a GTX 770. If you are afraid that 550w arent enough get the XFX 650.
Hope i helped