qmake-qt5: command not found

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 CentOS possible default full paths are:

/usr/bin/qmake-qt5 - from package: qt5-qtbase-devel
/usr/lib64/qt5/bin/qmake-qt5 - from package: qt5-qtbase-devel
/usr/lib/qt5/bin/qmake-qt5 - from package: qt5-qtbase-devel

You may install the required package with command yum install {package}

Error in other languages:
qmake-qt5: bevel nie gevind nie
qmake-qt5: comandă negăsită
qmake-qt5: comando não encontrado
qmake-qt5: commande introuvable
qmake-qt5: command not found
qmake-qt5: käsku ei ole
qmake-qt5: không tìm thấy lệnh
qmake-qt5: komanda nerasta
qmake-qt5: Kommando nicht gefunden.
qmake-qt5: kommandot finns inte
qmake-qt5: komut yok
qmake-qt5: nie znaleziono polecenia
qmake-qt5: níor aimsíodh an t-ordú
qmake-qt5: no se encontró la orden
qmake-qt5: no s'ha trobat l'ordre
qmake-qt5: opdracht niet gevonden
qmake-qt5: parancs nem található
qmake-qt5: perintah tidak ditemukan
qmake-qt5: príkaz nenájdený
qmake-qt5: příkaz nenalezen
qmake-qt5: команда не найдена
qmake-qt5: командата не е открита
qmake-qt5: 命令找不到
qmake-qt5: コマンドが見つかりません