Question

Identify the following as an expression or an equation.(4 points) Expression Equation 21⋅−3x21⋅−3x 2x−5=42x−5=4 −3x3=82−3x3=82 5x2−8x+25x2−8x+2

Answer 1

To identify the given mathematical statements as either expressions or equations, we can follow these definitions:

- **Expression**: A combination of numbers, variables, and operations (like addition, subtraction, multiplication, and division) without an equality sign.
- **Equation**: A mathematical statement that asserts the equality of two expressions, typically containing an equality sign (=).

Now, let's evaluate the given statements:

1. **21⋅−3x**
- This is an expression because it combines numbers and a variable but lacks an equality sign.

2. **2x−5=4**
- This is an equation because it presents two expressions (2x - 5 and 4) with an equality sign.

3. **−3x3=82**
- This is an equation because it asserts that −3x³ is equal to 82.

4. **5x2−8x+2**
- This is an expression because it is a polynomial without an equality sign.

### Summary:
- **Expressions**: 21⋅−3x, 5x2−8x+2
- **Equations**: 2x−5=4, −3x3=82