literal equation

Most equations you first meet have one letter standing for the unknown and plain numbers for everything else. A literal equation breaks that pattern: it is built from several letters, and your job is to solve for one of them while the others ride along as stand-ins for numbers.

Because the “numbers” are now letters, the answer comes out as an expression rather than a single value. You still isolate the chosen variable with the same inverse operations, treating every other letter as if it were a known constant.

Formulas are the most common literal equations, which is why solving one for a different variable — formula rearrangement — is exactly this skill applied. The result is a new formula, ready to plug numbers into later.