Hi Garrett! Yes, the HW-B750F can work with your LG B5's Magic Remote for basic functions such as volume, mute, and power when connected using HDMI ARC with HDMI-CEC (SIMPLINK) enabled on the TV.
If you're using an optical connection instead of HDMI ARC, some LG TVs may still be able to control the soundbar by setting up the Magic Remote as a universal remote, but compatibility and available functions can vary.
For the best experience, we recommend connecting the HW-B750F to your LG B5 via HDMI ARC and enabling SIMPLINK in the TV's settings. This provides the most reliable remote control functionality. ~ Samsung Solutions