Use the following examples and interactive exercises to learn about Writing Algebraic Expressions. Solution: Let g represent the number of groups in Ms. Jensen's class. Then 2 · g, or 2g can represent "g groups of 2 students". In the problem above, the variable g represents the number of groups in Ms. Jensen's class. A variable is a symbol used to represent a number in an expression or an equation. The value of this number can vary (change). Let's look at an example in which we use a variable. Example 1: Write each phrase as a mathematical expression.
The expression 9 + 8 represents a single number (17). This expression is a numerical expression, (also called an arithmetic expression). The expression 9 + x represents a value that can change. If x is 2, then the expression 9 + x has a value of 11. If x is 6, then the expression has a value of 15. So 9 + x is an algebraic expression. In the next few examples, we will be working solely with algebraic expressions. Example 2: Write each phrase as an algebraic expression.
In Example 2, each algebraic expression consisted of one number, one operation and one variable. Let's look at an example in which the expression consists of more than one number and/or operation. Example 3: Write each phrase as an algebraic expression using the variable n.
Solution: Let e represent the number of employees in the company. The amount of money each employee will get is represented by the following algebraic expression: Solution: Let x represent the number of hours the electrician works in one day. The electrician's earnings can be represented by the following algebraic expression: Solution: 45x - 20 Summary: A variable is a symbol used to represent a number in an expression or an equation. The value of this number can change. An algebraic expression is a mathematical expression that consists of variables, numbers and operations. The value of this expression can change. ExercisesDirections: Choose the algebraic expression that correctly represents the phrase provided. Select your answer by clicking on its button. Feedback to your answer is provided in the RESULTS BOX. If you make a mistake, choose a different button.
Sign Up For Our FREE Newsletter!Sign Up For Our FREE Newsletter!What is the algebraic expression of one half of a number?Halving a number means dividing it by two, so the expression that shows the half of a number is x2 , since you divide a number by two.
What does 7 more than a number mean?Suppose that "the number" is x . Then, to get a number which is " 7 more than that number" you have to add 7 in that no., 7 you get the answer x+7 .
What does 7 more than Y mean?Answer: If x is a number that is 7 more than y, then x as a function of y is expressed as f (y) = x = 7 + y.
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