Can S5735-L24T4S-A and S5735-L48T4X-A1 stack together?

Hi,
Yes, any models of the S5735-L can set up a stack. Any models of the S5735S-L can set up a stack.
When multiple switches set up a stack, member switches will synchronize the running version of the master switch. If a member switch does not support this running version, it will restart repeatedly.

For more information, you can refer to S5735-L, S5735S-L, and S5735S-L-M Service Port Stacking Support and Stack Configuration and Deployment Recommendations.

Hi, friend!
The S5735-L24T4S-A can be stacked with the S5735-L48T4X-A using SFP+ cables. The model of a1 is not queried. You can also use the following tool to query.

Stack & SVF Assistant

Hi,

No, Ports of two different types on a switch can be configured as stack ports simultaneously, except 1 Gbit/s and 10 Gbit/s ports. Each logical stack interface can contain only ports of the same rate.