3.1Two Step Equations.notebook
September 26, 2011
Solving Equations!!
Equation: A mathematical sentence that uses an equal sign
3.1
Solving Two­Step Equations
Aug 27­2:44 PM
Sep 14­8:19 PM
Solving Equations
Two step equations: Equations where two inverse operations are performed.
The equal sign designates the different "sides" of the equation
1. Find the variable. What are you solving for? How are the numbers related to the variable you're solving for?
2. Get the variable alone. Use inverse operations to isolate the variable. Always get rid of addition and subtraction first!
3. Remember that whatever you do to one side of the
equation you have to do to the other side!
17 = 3x + 5
The 5 is being added to x
This 3 is being multiplied to x.
1. Find the variable. What are you solving for? How are the numbers related to the variable you're solving for?
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Aug 27­3:06 PM
The inverse operation of multiplication is division.
The inverse operation of addition is subtraction.
17 = 3x + 5
The 5 is being added to x
This 3 is being multiplied to x.
2. Get the variable alone. Use inverse operations to isolate the variable. Aug 27­2:44 PM
Always get rid of addition and subtraction first!
17 = 3x + 5
­ 5
­ 5
12 = 3x + 0
12 = 3x 3. Remember that whatever you do to one side of the
equation you have to do to the other side!
Aug 27­3:23 PM
1
3.1Two Step Equations.notebook
September 26, 2011
2y ­ 3 = 9
17 = 3x + 5
­ 5
­ 5
12 = 3x
3
3
4 = 1x
x = 4
Whatever you do to one side of an equation you must do to the other!
If you start with an equation, you must have an asnwer that is an equation.
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­8 + x = ­3
3
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Homework #15
Page 122
#1­21 odd
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