"scale(.5) translateY(90%) rotate(55deg)""translateY(90%)"./translateY/ - возвращает 10.
> "scale(.5) translateY(12000px) rotate(55deg)".replace(/ translateY\(\d+.*?\)/, '')
'scale(.5) rotate(55deg)'
> "scale(.5) translateY(120%) rotate(55deg)".replace(/ translateY\(\d+.*?\)/, '')
'scale(.5) rotate(55deg)'