An equation, both of whose sides are rational expressions — in other words, it only includes numbers, literal symbols, arithmetical operations, and integral powers — is also rational. Solving a mathematical problem frequently presupposes deriving, then solving a rational equation. The student must first assign X as the independent variable. The variable, as a rule, stands for speed, time, or other physical parameters to calculate. The process of solving actually involves presenting a word problem in the form of an equation and solving it. Then the equation is solved, and its root is determined, which is the answer to the problem.
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