Struggling to get 3rd monitor working with graphics card

[Freekill98]

Hi, I am trying to set up 3 monitors for my pc. Two monitors works fine but 3rd is unrecongized by my graphics card. The graphics card I have is the R9 280X which should be able to support 3 monitors just fine. The ones I am using at the moment are; Dell 17" UltraSharp 1703FPt Flat Panel LCD Monitor, Viewsonic, VX2263Smhl-W and Akura AELD2YR26T7UH. Someone mentioned it might be because the refresh rates were different? so I was wondering what if I got another Dell monitor so it would be Dell 17" UltraSharp 1703FPt Flat Panel LCD Monitor (left), Viewsonic, VX2263Smhl-W (middle), Dell 17" UltraSharp 1703FPt Flat Panel LCD Monitor (right).

Do you think that would work? if not does anyone have any solutions? It's important I get this 3rd monitor working

 

[corroded]

What are you using to connect them? 1 connection MUST be an Active Displayport adapter...

 

[Freekill98]

Well I have tried all combinations I can think of. My Main (viewsonic) is HDMI, My 2nd (dell) is DVI I think (white plug) and if I plug in my third monitor I would use VGA, HDMI, or DP to HDMI but no dice regardless. I don't suppose I need a monitor with a DP slot over using a DP to HDMI?