
Algebraic ExpressionsVariables· Letters represent an unknown or generic real number · Sometimes with restrictions, such as a member of a certain set, or the set of values that makes an equation true. · Often a letter from the end of the alphabet: x, y, z · Or a letter that stands for a physical quantity: d for distance, t for time, etc. Constants· Fixed values, like 2 or 7. · Can also be represented by letters: a, b, c, p, e, k TermsTerms are Separated by + or – FactorsFactors are multiplied together. CoefficientsCoefficients are constant factors that multiply a variable or powers of a variable The middle term has 2 factors, –3 and x. We say that the coefficient of x is –3. The first term has three factors, 2 and two factors of x. We say that 2 is the coefficient of x^{2}. The last term is a factor all by itself (although the number 4 could be factored into 2 × 2). 
