Question on: JAMB Mathematics - 2012
The binary operation on the set of real numbers is defined by m*n = \(\frac{mn}{2}\) for all m, n \(\in\) R. If the identity element is 2, find the inverse of -5
A
\(-\frac{4}{5}\)
B
\(-\frac{2}{5}\)
C
4
D
5
Ask EduPadi AI for a detailed answer
Correct Option: A
m \(\propto\) n = \(\frac{mn}{2} - a\)
Identify = e = 2
a \(\propto\) a-1 = e
a \(\propto\) a-1 = 2
-5 \(\propto\) a-1 = 2
\(\frac{-5 \times a^{-1}}{2} = 2\)
\(a^{-1} = \frac{2 \times 2}{-5}\)
\(a^{-1} = -\frac{4}{5}\)
Identify = e = 2
a \(\propto\) a-1 = e
a \(\propto\) a-1 = 2
-5 \(\propto\) a-1 = 2
\(\frac{-5 \times a^{-1}}{2} = 2\)
\(a^{-1} = \frac{2 \times 2}{-5}\)
\(a^{-1} = -\frac{4}{5}\)
Add your answer
Please share this, thanks!
No responses