eqn2img: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/eqn2img - from package: gladtex

You may install the required package with command apt-get install {package}
Error in other languages:
eqn2img: bevel nie gevind nie
eqn2img: comandă negăsită
eqn2img: comando não encontrado
eqn2img: commande introuvable
eqn2img: command not found
eqn2img: käsku ei ole
eqn2img: không tìm thấy lệnh
eqn2img: komanda nerasta
eqn2img: Kommando nicht gefunden.
eqn2img: kommandot finns inte
eqn2img: komut yok
eqn2img: nie znaleziono polecenia
eqn2img: níor aimsíodh an t-ordú
eqn2img: no se encontró la orden
eqn2img: no s'ha trobat l'ordre
eqn2img: opdracht niet gevonden
eqn2img: parancs nem található
eqn2img: perintah tidak ditemukan
eqn2img: príkaz nenájdený
eqn2img: příkaz nenalezen
eqn2img: команда не найдена
eqn2img: командата не е открита
eqn2img: 命令找不到
eqn2img: コマンドが見つかりません