Algebraic expression With instance Problems and Interactive Exercises

Use the adhering to examples and also interactive practice to learn around Writing Algebraic Expressions.

You are watching: Fifteen more than half a number is 9


Problem: Ms. Jensen likes to division her course into groups of 2. Usage mathematical symbols to represent all the college student in her class.

Solution: Let g stand for the number of groups in Ms. Jensen"s class.

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

In the problem above, the variable g to represent the variety of groups in Ms. Jensen"s class. A variable is a symbol offered to stand for a number in an expression or an equation. The worth of this number can vary (change). Let"s watch at an instance in i m sorry we usage a variable.

Example 1: Write each expression as a mathematics expression.

Phrase Expression the sum of nine and also eight 9 + 8 the sum of nine and also a number x 9 + x

The expression 9 + 8 represents a solitary number (17). This expression is a numerical expression, (also referred to as an arithmetic expression). The expression 9 + x represents a worth that can change. If x is 2, climate the expression 9 + x has 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 next couple of examples, we will be working specifically with algebraic expressions.

Example 2: Write each expression as one algebraic expression.

Phrase Expression nine enhanced by a number x 9 + x fourteen lessened by a number p 14 - ns seven less than a number t t - 7 the product of 9 and also a number n 9 · n   or   9n thirty-two divided by a number y 32 ÷ y   or   

In example 2, each algebraic expression contained one number, one operation and one variable. Let"s look at an example in i m sorry the expression is composed of an ext than one number and/or operation.

Example 3: Write each phrase as one algebraic expression utilizing the variable n.

Phrase Expression five more than twice a number 2n + 5 the product of a number and 6 6n seven separated by twice a number 7 ÷ 2n   or   
3 times a number reduced by 11 3n - 11

Example 4: A small company has $1000 to distribution to the employees together a bonus. How much money will certainly each employee get?

Solution: Let e represent the variety of employees in the company. The lot of money every employee will acquire is represented by the complying with algebraic expression:


Example 5: An electrician fees $45 per hour and spends $20 a day on gasoline. Compose an algebraic expression to represent his revenue for one day.

Solution: Let x stand for the number of hours the electrician functions in one day. The electrician"s earnings can be stood for by the following algebraic expression:

Solution: 45x - 20

Summary: A variable is a symbol supplied to represent a number in one expression or an equation. The worth of this number deserve to change. An algebraic expression is a mathematical expression that is composed of variables, numbers and also operations. The value of this expression deserve to change.


Directions: pick the algebraic expression that correctly represents the expression provided. Choose your answer by clicking on its button. Feedback to your answer is noted in the outcomes BOX. If you do a mistake, pick a various button.

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1.  Fifteen much less than double a number     15 - 2x2x + 152x - 15None the the above.


2.  Three time a number, boosted by seventeen     3(a + 17)3a + 17(17 + 3)aNone the the above.


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


4.  Thirty divided by seven times a number     30 + 7n
30(7n) no one of the above.   outcomes BOX: 5.  Jenny earns $30 a work working component time in ~ a supermarket. Create an algebraic expression to represent the lot of money she will earn in d days.     30d
30 + d nobody of the over   outcomes BOX: