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VTRMC
1980 VTRMC
1
1980 VTRMC #1
1980 VTRMC #1
Source:
August 11, 2020
Problem Statement
Let
∗
*
∗
denote a binary operation on a set
S
S
S
with the property that
(
w
∗
x
)
∗
(
y
∗
z
)
=
w
∗
z
(w*x)*(y*z) = w * z
(
w
∗
x
)
∗
(
y
∗
z
)
=
w
∗
z
for all
w
,
x
,
y
,
z
∈
S
.
w,x,y,z\in S.
w
,
x
,
y
,
z
∈
S
.
Show(a) If
a
∗
b
=
c
,
a*b=c,
a
∗
b
=
c
,
then
c
∗
c
=
c
.
c*c = c.
c
∗
c
=
c
.
(b) If
a
∗
b
=
c
,
a*b=c,
a
∗
b
=
c
,
then
a
∗
x
=
c
∗
x
a*x=c*x
a
∗
x
=
c
∗
x
for all
x
∈
S
.
x\in S.
x
∈
S
.
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