iMac retrieve old linux partition after dual boot removal

On my iMac I installed a dual boot with Linux Mint. However, I realized that the videos were freezing some times, so I deleted the Linux partition. Now, the Mac is working normally, but instead of having a partition of 1 TB, I just have a 800GB's total space on my Hard Disk.

How can I do to retrieve the 200GB of space that were on the Linux partition I deleted?

Below is the output from diskutil list.

/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   #:                       TYPE NAME                    SIZE       IDENTIFIER 
   0:      GUID_partition_scheme                        *1.0 TB     disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                  Apple_HFS Macintosh HD            800.0 GB   disk0s2
   3:                  Apple_HFS Recovery HD             650.0 MB   disk0s3
   4: FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF               1.0 MB     disk0s4

Solution 1:

Generally, the commands below should work.

sudo diskutil erasevolume free none disk0s4
sudo diskutil resizevolume disk0s2 R