

echo $PATH
echo $LD_LIBRARY_PATH
PATH lists the locations of the executables and LD_LIBRARY_PATH lists where to look for shared libraries. Earlier entries are prioritized over later ones, and : is used to separate multiple entries. To tell the build program where to find the specific CUDA toolkit you want, insert the correct path to list first. This command prepends rather than overwrites the existing values.
```bash
adjust the version and full path if needed
export PATH=/usr/local/cuda-10.2/bin:$PATH
export LD_LIBRARY_PATH=/usr/local/cuda-10.2/lib64:$LD_LIBRARY_PATH