Algebra ExpressionsAlgebra Expressions
An algebraic expression is made up of the signs and symbols of algebra. These
symbols include the Arabic numerals, literal numbers, the signs of operation, and so
forth. Such an expression represents one number or one quantity.
Thus, just as the sum of 4 and 2 is one quantity, that is, 6, the sum of c and d is one
quantity, that is, c + d. Likewise , ab, a - b, and so forth, are algebraic expressions
each of which represents one quantity or number.
Longer expressions may be formed by combinations of the various signs of operation
and the other algebraic symbols, but no matter how complex such expressions are
they still represent one number. Thus the algebraic expression is one number
The arithmetic value of any algebraic expression depends on the values assigned to
the literal numbers. For example, in the expression 2x2 - 3ay, if x = -3, a = 5, and y =
1, then we have the following:KnowMoreAboutAnglesAndTheirMeasurements Tutorcircle.comPageNo.:1/4
2x2 - 3ay = 2(-3)2 -3(5)(1)
= 2(9) - 15 = 18 - 15 = 3
Notice that the exponent is an expression such as 2x2 applies only to the x. If it is
desired to indicate the square of 2x, rather than 2 times the square of x, then
parentheses are used and the expression becomes (2x)2.
Practice problems. Evaluate the following algebraic expressions when a = 4, b = 2, c
= 3, x = 7, and y = 5. Remember, the order of operation is multiplication, division,
addition, and subtraction.TERMS AND COEFFICIENTS
The terms of an algebraic expression are the parts of the expression that are
connected by plus and minus signs. In the expression 3abx + cy - k, for example,
3abx, cy, and k are the terms of the expression.
An expression containing only one term, such as 3ab, is called a monomial (mono
means one). A binomial contains two terms; for example, 2r + by. A trinomial consists
of three terms. Any expression containing two or more terms may also be called by
the general name, polynomial (poly means many).
Usually special names are not given to polynomials of more than three times. The
expression x3 - 3x2 + 7x + 1 is a polynomial of four terms. The trinomial x2 + 2x + 1 is
an example of a polynomial which has a special name.
Practice problems. Identify each of the following expressions as a monomial,
binomial, trinomial, or polynomial. (Some expressions may have two names.)ReadMoreAboutAddingDecimalsCalculator Tutorcircle.comPageNo.:2/4
n general, a COEFFICIENT of a term is any factor or group of factors of a term by
which the remainder of the term is to be multiplied. Thus in the term 2axy, 2ax is the
coefficient of y, 2a is the coefficient of xy, and 2 is the coefficient of axy. The word
"coefficient" is usually used in reference to that factor which is expressed in Arabic
This factor is sometimes called the NUMERICAL COEFFICIENT. The numerical
coefficient is customarily written as the first factor of the term. In 4x, 4 is the numerical
coefficient, or simply the coefficient, of x.
Likewise, in 24xy2, 24 is the coefficient of xy2 and in 16(a + b), 16 is the coefficient of
(a + b). When no numerical coefficient is written it is understood to be 1. Thus in the
term xy, the coefficient is 1.COMBINING TERMS
When arithmetic numbers are connected by plus and minus signs, they can always
be combined into one number. Thus,
Here three numbers are added algebraically (with due regard for sign) to give one
number. The terms have been combined into one term. Terms containing literal
numbers can be combined only if their literal parts are the same. Terms containing
literal factors in which the same letters are raised to the same power are called like
For example, 3y and 2y are like terms since the literal parts are the same. Like terms
are added by adding the coefficients of the like parts. Thus, 3y + 2y = 5y just as 3
bolts + 2 bolts = 5 bolts. Also 3a2b and a2b are like; 3a2b + a2b = 4a2b and 3a2b -
a2b = 2a2b. TutTu ot rcr ic rcr lc el .e c. oc mPaP geg e NoN ..::2/3 3/4