Answer
The number $0$ has no multiplicative inverse because the definition of a multiplicative inverse is that if you multiply a number by its multiplicative inverse, you get $1$. Since $0$ cannot be multiplied by anything to get $1$, $0$ does not have a multiplicative inverse.
Work Step by Step
The number $0$ has no multiplicative inverse because the definition of a multiplicative inverse is that if you multiply a number by its multiplicative inverse, you get $1$. Since $0$ cannot be multiplied by anything to get $1$, $0$ does not have a multiplicative inverse.