CHMOD + X

https://unix.stackexchange.com/questions/639438/whats-the-difference-between-chmod-ax-and-chmod-x 

From man chmod:

A combination of the letters ugoa controls which users' access to the
file will be changed: the user who owns it (u), other users in the
file's group (g), other users not in the file's group (o), or all users
(a).  If none of these are given, the effect is as if (a) were given,
but bits that are set in the umask are not affected.

Assuming you have the proper permissions,

• a+x will set all the x bits of the file.

• +x will set all the x bits of the file that are not present in the umask.

Example:

$ umask
0022       # The group and other write bits are set

$ ls -l
---------- file

$ chmod +x file; ls -l
---x--x--x file

$ chmod +w file; ls -l
--wx--x--x file

$ chmod a+w file; ls -l
--wx-wx-wx file