y, n, or t. Expression: An expression is a mathematical statement that may use numbers, variables or both. An expression does not have an equal sign. Example: x + 2. Equation: An equation is a mathematical statement that two numbers or expressions are equal...
Watch out for phrases like "400 volts of alternating current". Current does not have units of volts. As a related matter, use the same measure consistently. For example, do not compare costs per year with costs per month. Be careful to distinguish among objects, properties of objects, and...