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Writing Equations for Lines Using Sequences
Intersections of Lines and Conics
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Quadratic Expresions - Complete Squares
Adding and Subtracting Fractions with Like Denominators
Multiplying a Fraction by a Whole Number
Solving Equations with Log Terms and Other Terms
Solving Quadratic Equations by Factoring
Locating the Solutions of the Quadratic Equation
Properties of Exponents
Solving Equations with Log Terms on Each Side
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Graphs of Trigonometric Functions
Estimating Products and Quotients of Mixed Numbers
Inequalities
The circle
Adding Polynomials
Adding Fractions with Unlike Denominators
Factoring Polynomials
Linear Equations
Powers of Ten
Straight Lines
Dividing With Fractions
Multiplication Property of Equality
Rationalizing Denominators
Multiplying And Dividing Fractions
Distance Between Points on a Number Line
Solving Proportions Using Cross Multiplication
Using the Quadratic Formula
Scientific Notation
Imaginary Numbers
Values of Symbols for Which Fractions are Undefined
Graphing Equations in Three Variables
Writing Fractions as Decimals
Solving an Equation with Two Radical Terms
Solving Linear Systems of Equations by Elimination
Factoring Trinomials
Positive Rational Exponents
Adding and Subtracting Fractions
Negative Integer Exponents
Rise and Run
Brackets
Multiplying Square Roots
Multiplying Polynomials
Solving Systems of Linear Inequalities
Multiplication Property of Radicals
A Quadratic within a Quadratic
Graphing a Linear Equation
Calculations with Hundreds and Thousands
Multiplication Property of Square and Cube  Roots
Solving Equations with One Log Term
The Cartesian Coordinate Plane
Equivalent Fractions
Adding and Subtracting Square Roots
Solving Systems of Equations
Exponent Laws
Solving Quadratic Equations
Factoring Trinomials
Solving a System of Three Linear Equations by Elimination
Factoring Expressions
Adding and Subtracting Fractions
The parabola
Computations with Scientific Notation
Quadratic Equations
Finding the Greatest Common Factor
Introduction to Fractions
Simplifying Radical Expressions Containing One Term
Polynomial Equations
Graphing and Intercepts
The Number Line
Adding and Subtracting Rational Expressions with Different Denominators
Scientific Notation vs Standard Notation
Powers
Factoring by Grouping
Extraneous Roots
Variables and Expressions
Linera Equations
Integers and Substitutions
Squares and Square Roots
Adding and Subtracting Rational Expressions with Different Denominators
Solving Linear Inequalities
Expansion of a Product of Binomials
Powers and Exponents
Finding The Greatest Common Factor
Quadratic Functions
The Intercepts of a Parabola
Solving Equations Containing Rational Expressions
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Subtracting Polynomials
Solving Equations
Adding Fractions with Unlike Denominators
Solving Systems of Equations by Substitution
Solving Equations
Product and Quotient of Functions
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Variables and Expressions

After completing this lesson, you will be able to:

  • Write mathematical expressions using verbal expressions
  • Define variable and algebraic expression

In algebra, letters are often used to represent numbers. These are called variables. An algebraic expression is a mathematical statement which at least one number and at least one variable along with at least one arithmetic operation.

Example 1

Write an algebraic expression for the difference of x and 7.

The word difference means subtract, so the algebraic expression would be x - 7

This is an algebraic expression because it contains at least one number (7), at least one variable (x), and at least one arithmetic operation (subtraction).

Example 2

Write an algebraic expression for the number y added to 4 times the number x.

This would be written as y + 4x

The 4x means 4 times the number x

Example 3

Write an algebraic expression for the sum of twelve and the product of five and x.

The word sum means to add.

The word product means to multiply. Therefore, our algebraic expression would be 12 + 5x

Example 4

Write a verbal expression for z + 10.

This time, we are taking an algebraic expression and translating it to a verbal expression.

The term for + is sum. Therefore, we would write the sum of z and ten

Example 5

Write a verbal expression for 10xy. Since the only operation here is multiplication, we could write ten times x times y or we Could write times the product of x and y. Either expression is correct.

In the expression , 10 is called the base and 3 is called the exponent . The meaning of this expression is 10 · 10 · 10 . If you were asked to find the answer you would multiply 10 · 10 · 10 and get 1000. This is called evaluating the expression. The algebraic expression 4 · x · x · x · y · y could be written using exponents. The new expression would be . The algebraic expression 4 · 4 · x · y · y · y could be written using exponents. The new expression would be or it could also be written because is the same as 16.

Example 6

Evaluate the expression Evaluate simply means that we want to find an answer. Remember that means 2 · 2 · 2 · 2 · 2 . (It does not mean 2 times 5). Since 2 · 2 · 2 · 2 · 2 is 32, that is the answer.

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