Final answer:
The best definition of an algebraic expression is a mathematical phrase that includes variables, numbers, and operations. It can be part of an equation or inequality, useful in algebra to solve for unknown variables, especially in linear equations.
Step-by-step explanation:
The definition that best fits the term algebraic expression is B: A mathematical phrase involving one or more variables, numbers, and operations. Unlike an equation that shows equality, an algebraic expression does not need to equate to something; it is more like a fragment of an equation or an inequality, consisting of terms that can include variables like x or y, constants, and various arithmetic operations such as addition, subtraction, multiplication, and division.
As with any equation, when you know all but one variable in the expression for q, you can determine the remaining variable using algebra. This process is an integral aspect of solving linear equations, like the fundamental y = mx + b, where x and y are the variables affected by constants m (slope) and b (y-intercept).