For openSUSE Tumbleweed PowerPC run the following as root:
zypper addrepo https://download.opensuse.org/repositories/windows:mingw:win64/openSUSE_Tumbleweed_PowerPC/windows:mingw:win64.repo
zypper refresh
zypper install mingw64-gtkmathview
For openSUSE Tumbleweed ARM run the following as root:
zypper addrepo https://download.opensuse.org/repositories/windows:mingw:win64/openSUSE_Tumbleweed_ARM/windows:mingw:win64.repo
zypper refresh
zypper install mingw64-gtkmathview
For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/windows:mingw:win64/openSUSE_Tumbleweed/windows:mingw:win64.repo
zypper refresh
zypper install mingw64-gtkmathview