Home » Classroom » JAMB Mathematics 2007 Question

A binary operation is defined by a b a b 1 for ... - JAMB Mathematics 2007 Question

A binary operation Δ is defined by aΔb = a + b + 1 for any numbers a and b. Find the inverse of the real number 7 under the operation Δ, if the identity element is -1
A
-7
B
-9
C
5
D
9
correct option: b

a*e = a + e + 1 = a

implies e+ 1 = 0

∴ e = -1

7 * e = -1

∴ a + 7 + 1 = -1

a + 8 = -1

a+8 = -1

a = -1-8

a = -9

Please share this, thanks:

#JAMB #JAMB

Add your answer

Notice: Please post responsibly.

No responses