What is the definition of a solution in mathematics?

In mathematics, a solution is specifically defined as a number or set of numbers that satisfies an equation or makes it true. This concept is fundamental when solving equations, as the goal often involves finding values that will make both sides of the equation equal. For example, in the equation (x + 2 = 5), the value (x = 3) is a solution because substituting it into the equation results in a true statement: (3 + 2 = 5).

The other options do not capture this definition accurately. The second choice refers to a variable, which is part of the equation but does not imply a specific numeric value that solves it. The third choice relates to inequalities, which are a different concept; while solutions can exist for inequalities, they are not considered solutions in the context of equations. The final option describes an initial action in problem-solving rather than defining a solution itself. Therefore, the correct understanding of a solution is that it is a number that makes an equation true.