How to write an equation

5th Grade,

Here is more information on how to write an equation.  Get good at this and you'll have a greater chance at success in middle and high school math.

http://www.mathgoodies.com/lessons/vol7/equations.html

Problem:	Jeanne has $17 in her piggy bank. How much money does she need to buy a game that costs $68?
Solution:	Let x represent the amount of money Jeanne needs. Then the following equation can represent this problem:
	17 + x = 68
	We can subtract 17 from both sides of the equation to find the value of x.
	68 - 17 = x
Answer:	x = 51, so Jeanne needs $51 to buy the game.

In the problem above, x is a variable. The symbols 17 + x = 68 form an algebraic equation. Let's look at some examples of writing algebraic equations.

Example 1:	Write each sentence as an algebraic equation.
	Sentence Algebraic Equation A number increased by nine is fifteen. y + 9 = 15 Twice a number is eighteen. 2n = 18 Four less than a number is twenty. x - 4 = 20 A number divided by six is eight.

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Example 2:	Write each sentence as an algebraic equation.
	Sentence Algebraic Equation Twice a number, decreased by twenty-nine, is seven. 2t - 29 = 7 Thirty-two is twice a number increased by eight. 32 = 2a + 8 The quotient of fifty and five more than a number is ten. Twelve is sixteen less than four times a number. 12 = 4x - 16

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Example 3:	Write each sentence as an algebraic equation.
	Sentence Algebraic Equation Eleni is x years old. In thirteen years she will be twenty-four years old. x + 13 = 24 Each piece of candy costs 25 cents. The price of h pieces of candy is $2.00. 25h = 200 or .25h = 2.00 Suzanne made a withdrawal of d dollars from her savings account. Her old balance was $350, and her new balance is $280. 350 - d = 280 A large pizza pie with 15 slices is shared among p students so that each student's share is 3 slices.

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Summary:

An algebraic equation is an equation that includes one or more variables. In this lesson, we learned how to write a sentence as an algebraic equation.