Which out of the following are expressions with numbers only?
(a) `y + 3` (b) `(7 xx 20) – 82`
(c) `5 (21 - 7) + 7 xx 2` (d) `5`
(e) `3x ` (f) `5-5n`
(g) `(7 xx 20) - (5 xx 10) - 45+ p`

Answer

To determine which of the given expressions are expressions with numbers only, we need to identify whether each expression contains any variables (like x, y, or p). An expression with numbers only will consist solely of numerical values and operations.

Let's analyze each option step by step:

1. **Option (a): `y + 3`**
- This expression contains the variable `y` and the number `3`.
- **Conclusion:** Not a number-only expression.

2. **Option (b): `(7 xx 20) – 82`**
- This expression contains the numbers `7`, `20`, and `82`, and uses arithmetic operations.
- **Conclusion:** This is a number-only expression.

3. **Option (c): `5 (21 - 7) + 7 xx 2`**
- This expression contains the number `5`, the result of `(21 - 7)` which is `14`, and `7` and `2` in the multiplication.
- **Conclusion:** This is a number-only expression.

4. **Option (d): `5`**
- This expression consists solely of the number `5`.
- **Conclusion:** This is a number-only expression.

5. **Option (e): `3x`**
- This expression contains the variable `x` and the number `3`.
- **Conclusion:** Not a number-only expression.

6. **Option (f): `5 - 5n`**
- This expression contains the variable `n` and the number `5`.
- **Conclusion:** Not a number-only expression.

7. **Option (g): `(7 xx 20) - (5 xx 10) - 45 + p`**
- This expression contains the variable `p` along with numbers `7`, `20`, `5`, `10`, and `45`.
- **Conclusion:** Not a number-only expression.

### Final Answers:
The expressions that are numbers only are:
- (b) `(7 xx 20) – 82`
- (c) `5 (21 - 7) + 7 xx 2`
- (d) `5`

### Summary:
The expressions with numbers only are:
- **(b)** `(7 xx 20) – 82`
- **(c)** `5 (21 - 7) + 7 xx 2`
- **(d)** `5`