If the slots matches the pin configuration of the GPU it may work but there are considerations. Some GPUs have specific voltage requirements and some PCI Express 3.0 slots are not capable of clocking down to the 2.0 spec. You would need to look at the specifications of both the GeForce GT730 and the motherboard vendor's PCIe 3.0 x16 slot.
I have seen several boards that have dual 3.0 X16 slots with one that is limited to the 3.0 spec and voltage requirements and a second that is compatible with both 3.0 and 2.0; while others had both slots compatible with both specs. Sorry no references at the moment, ASUS had several as did MSI. In some of these systems they were often on the mATX boards while the full ATX boards had more RAM slots and more flexibility