Determine the neutral element of the law of composition xy
Determine the neutral element of the law of composition x*y = 3xy + 6(x+y) + 10
Solution
We have to determine the neutral element for x*y = 3xy + 6(x+y) + 10
To find this, let the neutral element be N, now x*N = e*N = x
From the given expression:
x*N = 3xN + 6(x+N) + 10
As this is also equal to x
=>3xN + 6(x+N) + 10 = x
=> 3xN + 6x + 6N + 10 = x
=> 3xN + 6N = x - 6x - 10
=> 3xN + 6N = -5x - 10
=> 3N ( x + 2) = -5x - 10
=> 3N ( x + 2) = -5 (x + 2)
=> 3N = -5
=> N = -5/3
So the neutral element is -5 /3.
