What is an identity, and what is its solution?

Question

Accepted Answer

C. True for any value; the solution is all real numbers

1. The definition names an equation true for any value of the variable an identity.
2. Since it holds for every possible value, the solution of an identity is stated as all real numbers.
3. An equation true for only one value is conditional instead, and one false for every value is a contradiction, neither of which matches this definition.
_Source: OpenStax Elementary Algebra (CC BY 4.0), Ch 2 "Solving Linear Equations and Inequalities", section 2.4 Use a General Strategy to Solve Linear Equations_

Answer

True for only one value; the solution is that number

Answer

False for every value; there is no solution at all

Answer

Written with two different variables inside it