Algebraic Expressions With Example Problems and Interactive Exercises

Use the complying with examples and also interenergetic exercises to learn about Writing Algebraic Expressions.

You are watching: Seven less than twice a number equals 19

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Problem: Ms. Jensen likes to divide her class into teams of 2. Use mathematical signs to recurrent all the students in her course.

Solution: Let g represent the number of groups in Ms. Jensen"s course.

Then 2 · g, or 2g have the right to represent "g teams of 2 students".

In the difficulty above, the variable g represents the number of groups in Ms. Jensen"s course. A variable is a symbol supplied to represent a number in an expression or an equation. The worth of this number have the right to differ (change). Let"s look at an example in which we usage a variable.

Example 1: Write each expression as a mathematical expression.

PhraseExpression
the amount of nine and eight9 + 8
the amount of nine and also a number x9 + x

The expression 9 + 8 represents a single number (17). This expression is a numerical expression, (likewise referred to as an arithmetic expression). The expression 9 + x represents a value that deserve to adjust. If x is 2, then the expression 9 + x has actually a worth of 11. If x is 6, then the expression has a worth of 15. So 9 + x is an algebraic expression. In the following few examples, we will certainly be functioning exclusively via algebraic expressions.

Example 2: Write each phrase as an algebraic expression.

PhraseExpression
nine increased by a number x9 + x
fourteenager lessened by a number p14 - p
salso less than a number tt - 7
the product of 9 and also a number n· n or 9n
thirty-2 split by a number y32 ÷ y or
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In Example 2, each algebraic expression consisted of one number, one procedure 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.

PhraseExpression
five even more than twice a number2n + 5
the product of a number and 66n
salso separated by twice a number÷ 2n or
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three times a number diminished by 113n - 11

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Example 4: A tiny agency has $1000 to distribute to its employees as a bonus. How a lot money will each employee get?

Solution: Let e recurrent the number of employees in the agency. The amount of money each employee will obtain is stood for by the following algebraic expression:

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Example 5: An electrician charges $45 per hour and spends $20 a day on gasoline. Write an algebraic expression to recurrent his revenue for someday.

Solution: Let x represent the number of hours the electrician works in at some point. The electrician"s revenue deserve to be stood for by the adhering to algebraic expression:

Solution: 45x - 20

Summary: A variable is a symbol supplied to reexisting a number in an expression or an equation. The value of this number have the right to change. An algebraic expression is a mathematical expression that is composed of variables, numbers and operations. The worth of this expression have the right to adjust.

Exercises

Directions: Choose the algebraic expression that properly represents the phrase provided. Select your answer by clicking its button. Feedback to your answer is provided in the RESULTS BOX. If you make a mistake, choose a various switch.

1. Fifteenager less than twice a number 
 15 - 2x2x + 152x - 15Namong the over.

RESULTS BOX: 

2. Three times a number, boosted by seventeen 
 3(a + 17)3a + 17(17 + 3)aNone of the over.

RESULTS BOX: 

3. The product of nine and also a number, lessened by six 
 9(m - 6)6(9 - m)9m - 6None of the above.

RESULTS BOX: 

4. Thirty divided by seven times a number 
 30 + 7n
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30(7n)
Namong the above.

See more: What Is The Electron Configuration For Arsenic ? Arsenic » Properties Of Free Atoms

 
RESULTS BOX:
5. Jenny earns $30 a day functioning component time at a supersector. Write an algebraic expression to reexisting the amount of money she will earn in d days. 
 30d
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30 + d
None of the above
 
RESULTS BOX: