Search SchoolNGR

Friday, 06 March 2026
Register . Login

If the binary \(\ast\) is defined by m \(\ast\) n = mn + m + n for any real number m ...

If the binary \(\ast\) is defined by m \(\ast\) n = mn + m + n for any real number m and n, find the identity of the elements under this operation
Take Free Practice Test On 2026 JAMB UTME, Post UTME, WAEC SSCE, GCE, NECO SSCE
  • A E = 1
  • B E = -1
  • C E = -2
  • D E = 0
Correct Answer: Option D
Explanation:
Identity(e) : a \(\ast\) e = a
m \(\ast\) e = m...(i)
m \(\ast\) e = me + m + e
Because m \(\ast\) e = m
: m = me + m + e
m - m = e(m + 1)
e = \(\frac{0}{m + 1}\)
e = 0

Share question on: