In this lesson we look at solving four types of one step equations by applying opposites to both sides. To obtain a PowerPoint format download of this presentation, go to the following page: http://passyworldofmathematics.com/pwerpoints/

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2. “Opposite” operations are used to solve equations.
Operation Opposite Example with (Opposite to Apply)
Addition Subtraction N+5 ( - 5 both sides)
Subtraction Addition Y – 17 ( + 17 both sides)
Multiplication Division 4h ( /4 both sides)
Division Multiplication k/8 ( x 8 both sides)
Square Root Square 3 m ( Square both sides)
Fraction Reciprocal 2F/3 ( x 3/2 both sides)

3. One Step Addition Example
The Opposite of Addition is Subtraction
y + 14 = 20
-14 -14
y = 6
The value which makes the equation true is 6.

4. The Opposite of Subtraction is Addition
x - 120 = 80
+120 +120
x = 200
The value which makes the equation true is 200.

5. Multiplication Example
The Opposite of Multiplication is Division
3n = 12
3/3 cancels down
3n = 12 to become 1/1 =1
3 3
n = 4 1n is simply “n”
The value which makes the equation true is 4.

6. The Opposite of Division is Multiplication.
k = 16 K is divided by 2,
so we need to multiply
2 both sides by 2
k x2 = 16 x 2 2/2 cancels down
to become 1/1 =1
2
k = 32 1k is simply “k”
The value which makes the equation true is 32.

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