Question

what is the multiplicative inverse of -9?

select one:
a. 0
b. \\(\frac{1}{9}\\)
c. 9
d. \\(-\frac{1}{9}\\)

Explanation:

Define multiplicative inverse

$$ x \cdot y = 1 \implies y = \frac{1}{x} $$

Substitute the given value

$$ x = -9 \implies y = \frac{1}{-9} = -\frac{1}{9} $$

Match with the options

$$ \text{Option d is } -\frac{1}{9} $$

Answer:

• a. 0
• b. \(\frac{1}{9}\)
• c. 9
• d. \(-\frac{1}{9}\) (Correct answer)