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Let us learn about what an algebraic expression is before learning about the terms of an algebraic expression. An algebraic expression is a concept of expressing numbers by using letters such as a, b, m, n, x, y, z, etc. without specifying their actual values.
An algebraic expression is a mathematical statement where variables have been combined using basic arithmetic operations such as addition, subtraction, multiplication, or division. The variables are the unknown values such as a, b, x, y, z, etc. A coefficient is a value that is placed before and multiplied by a variable, while a constant is a fixed numerical value.
Variables, coefficients, constants, and terms are different components of an algebraic expression. For example, mx + c is an algebraic expression, where "m" is the coefficient, "x" is the variable, and "c" is a constant. "mx" and "c" are terms of the given algebraic expression.
Example: Determine the like terms in the given algebraic expression: 4x2 โ 12x โ 3x3 + 8x + 10.
Solution:
Given expression: 4x2 โ 12x โ 3x3 + 8x + 10
= 4x2 + (โ12x) + (โ3x3) + 8x + 10
We know that like terms are those that have the same variables.
Here, (โ12x) and 8x are like terms, while 4x2, (โ3x3) and 10 are unlike terms.
There are various kinds of algebraic expressions depending upon the number of terms, and the highest degree of terms.
Type of Algebraic Expression | Definition | Examples |
|---|---|---|
Monomial | An algebraic expression with one term is a monomial. | 12ab, 3x2, 2p/7, etc. |
Binomial | An algebraic expression with two monomials is a binomial. | 3x+6y, 8p2+5q, etc |
Trinomial | An algebraic expression with three monomials is a trinomial. | 2x+4y+9z, etc |
Polynomial | An algebraic expression having two or more terms with non-negative exponents is a polynomial. | ax2+bx+c, 5x3+2y+4xz+8, etc. |
When the polynomial is represented in its standard form, the degree is the highest integral power of the variables of its terms. If the term has more than one variable, then the degree is equal to the sum of the exponents of the variables.
The general algebraic formulas we use for solving the expressions or equations are:
- (x + a) (x + b) = x2 + x(a + b) + ab
- (a + b)2 = a2 + 2ab + b2
- (a โ b)2 = a2 โ 2ab + b2
- (a + b)2 + (a โ b)2 = 2 (a2 + b2)
- (a + b)2 โ (a โ b)2 = 4ab
- a2 โ b2 = (a โ b)(a + b)
- (a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ca
- (a + b)3 = a3 + b3 + 3ab(a + b)
- (a โ b)3 = a3 โ b3 โ 3ab(a โ b)
- a3 โ b3 = (a โ b)(a2 + ab + b2)
- a3 + b3 = (a + b)(a2 โ ab + b2)
- a3 + b3 + c3 โ 3abc = (a + b + c)(a2 + b2 + c2 โ ab โ bc โ ca))
A coefficient is a number multiplied by a variable. Coefficient is a numerical factor that accompanies a variable or is multiplied by the variable in a term. It signifies the number by which the variable is scaled.
For instance, in the term 7x,7 is the coefficient. If a variable appears without an explicit numerical factor, it has an implied coefficient of 1, such as in the term z where the coefficient is 1. Similarly, in the expression, Similarly, in the expression 3??, 3 is the coefficient.
7 is the coefficient of the term โ7ab2.
When there is no numerical factor in a term, its coefficient is taken as +1. For example, in the term x2y3, the coefficient is +1.
In the term โx, the coefficient is -1.
What is an Expression and What are the types of Expressions? |
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Example 1: Determine the variable, coefficient, constant, and terms of the algebraic expression 31mn โ 16m + 4n + 19.
Solution:
Given expression: 31mn โ 16m + 4n + 19
= 31mn + (โ16m) + 4n + 19
Variables: mn, m, and n.
Terms: 31mn, (โ16m), 4n, and 19.
Constant: 19
Coefficients: 31 is the coefficient of mn,
โ16 is the coefficient of m, and
4 is the coefficient of n.
Example 2: Identify the terms, like terms, coefficients, and constants in the expressions given below.
a) 8xy โ 13x2 + 14x + 5y โ 21
b) x2 + 5x + 7 โ 15x
Solution:
a) Given expression: 8xy โ 13x2 + 14x + 5y โ 21
= 8xy + (โ13x2) + 14x + 5y + (โ21)
The terms of the given expression are 8xy, (โ13x2), 14x, 5y, and (โ21).
We know that like terms are those that have the same variables.
The given expression doesn't have any like terms.
Constant: (โ21).
8 is the coefficient of xy, (โ13) is the coefficient of x2, 14 is the coefficient of x, and 5 is the coefficient of y.
Hence, the coefficients are 8, (โ13), 14, and 5.
b) Given expression: x2 + 5x + 7 โ 15x
= x2 + 5x + 7 + (โ15x)
The terms of the given expression are x2, 5x, 7, and (โ15x).
We know that like terms are those that have the same variables.
Here the like terms are 5x and (โ15x).
Constant: 7.
1 is the coefficient of x2, 5 is the coefficient of x, and (โ15) is the coefficient of x.
Hence, the coefficients are 1, 5, (โ15).
Example 3:Determine the value of y in the equation 5y โ 13 = 2y + 17.
Solution:
Given,
5y โ 13 = 2y + 17
โ5y โ 2y = 17 + 13
โ 3y = 30
โ y = 30/3
โ y = 10.
Therefore the value of y in the equation 5y โ 13 = 2y + 17 is 10.
Example 4: Identify the terms, like terms, coefficients, and constants of the algebraic expression 10x3 + 71x2 + 91x โ 20x2 + 61.
Solution:
Given expression: 10x3 + 71x2 + 91x โ 20x2 + 61
= 10x3 + 71x2 + 91x + (โ20x2) + 61.
Terms: 10x3, 71x2, 91x , (โ20x2), and 61.
Constant: 61
Coefficients: 10 is the coefficient of x3, 71 is the coefficient of x2, 91 is the coefficient of x, and (โ20) is the coefficient of x2.
Like terms: 71x2 and (โ20x2).