LXV
If you mean as in Roman numerals then: C -XL = LX => 100 -40 = 60
40 in roman numerals is XL (10 less than 50) and 60 is LX (10 more than 50).
XL is 40, L is 50, LX is 60, LXX is 70, LXXX is 80
Xl = -10+50 = 40
It is: 40 = XL
40 in Roman numerals are XL or XXXX
40
XL
XL
XL
XL
550Improved Answer:-XL = 40