Fill in the blanks. (i) Zero has reciprocal. (ii) The numbers and are their own reciprocals (iii) The reciprocal of `(−5)` is. (iv) Reciprocal of `1 /x,` where `x != 0` is. (v) The product of two rational numbers is always a. (vi) The reciprocal of a positive rational number is.

Explanation

Let's solve the fill-in-the-blanks step by step.

### Step 1: Zero has a reciprocal.
- **Answer**: Zero does not have a reciprocal. The reciprocal of a number \( x \) is defined as \( \frac{1}{x} \). Since division by zero is undefined, zero has no reciprocal.

### Step 2: The numbers ___ and ___ are their own reciprocals.
- **Answer**: The numbers \( 1 \) and \( -1 \) are their own reciprocals.
- For \( 1 \): The reciprocal is \( \frac{1}{1} = 1 \).
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