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Modular Arithmetic
easy
0:00.0
Find
x
x
x
if
x
≡
−
1
(
m
o
d
10
)
x \equiv -1 \pmod{10}
x
≡
−
1
(
mod
10
)
.
A
−
1
-1
−
1
B
9
9
9
C
19
19
19
D
Both b and c
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