Can u run gpus on old prebuilt mobos and pro

i was trying to buy a cheap old pc for mining it was a dell vostro 660 it had 3 pcie 2x slot and one pcie 16x slot on intel b75 mobo with i3 3rd gen when i was checking for display it would not give display with a 580 but it would without it so what would be the prob i was gonna put 4 580 on it but it wont give display on 1 so how would it give display on 4

can anybody tell me how its do able so i can save some money for gpus XD

thanks in advance