"X" in Roman numerals is 10.
Roman Numeral Chart
I=1
V=5
X=10
L=50
C=100
D=500
M=1000
10 is equal to X in roman numerals
XL
50 Roman numerical values: M=1000, D=500, C=100, L=50, X=10, V=5, I=1
xxvi-x-mmiv
20
Hindu-Arabic numerical system is what we use today i.e. 0 1 2 3 4 5 6 7 8 and 9 Roman numerical system was once used in the past i.e. I V X L C D and M
The numerical coeffecient of -x is -1.
x2 - 81y2 = (x + 9y) (x - 9y)The actual numerical value depends on the values of 'x' and 'y'.
In Roman numerals the numerical value is 3000
VII
Numerical system of the Roman Empire
CX