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A binary operation * is defined by a*b = ab+a+b for any r...

A binary operation * is defined by a*b = ab+a+b for any real number a and b. if the identity element is zero, find the inverse of 2 under this operation.

A.

2/3

B.

1/2

C.

-1/2

D.

-2/3

Correct answer is D

aa1=aa1+a+a1=e

if e = 0

2.21+2+21=0

collecting like terms, we have:

3.21+2=0

= 21 = -23