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:
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21⋅−3x
- This is an expression because it combines numbers and a variable but lacks an equality sign.
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2x−5=4
- This is an equation because it presents two expressions (2x - 5 and 4) with an equality sign.
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−3x3=82
- This is an equation because it asserts that −3x³ is equal to 82.
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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