Identity element - Jamb Mathematics Past Questions and Answers

Question 11:

• JAMB 2009

A binary operation ⊗ defined on the set of integers is such that m⊗n = m + n + mn for all integers m and n. Find the inverse of -5 under this operation, if the identity element is 0

A. -⁵/₄
B. -⁵/₆
C. Zero
D. 5

Question 12:

• JAMB 2021

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

A. E = 1
B. E = -1
C. E = -2
D. E = 0