Algebra Period 4

ABSOLUTE VALUE EQUATIONS:Section 3-8

Review of SOLVING equations:

1. Clear both sides of any decimals or fractions

2. Distribute if necessary (or divide both sides if compatible number)

3. Collect like terms on the SAME SIDE of the equation

4. Use the additive inverse to move any variables on BOTH SIDES of the equation

5. Use the addition property of equality and
then the multiplication property of equality to isolate the variable.


Generally, you solve these the same way you solve regular equations.

Make sure you balance equally on both sides!


Follow the steps of a 2 step equation.

1. Add the opposite (you can subtract as well)

2. Multiply by the reciprocal (you can divide as well)


THE DIFFERENCE?
YOU HAVE 2 POSSIBLE ANSWERS! (+ and -)


EXAMPLE: 2 l x l + 1 = 15

2 l x l + 1 - 1 = 15 - 1

2 l x l = 14

1/2 ( 2 l x l ) = 1/2 (14)

l x l = 7

x = {-7, 7}



Remember: If you get that the absolute value is negative, the answer is the NULL SET-- just like before!!

EXAMPLE: 2 l x l + 16 = 15

2 l x l + 1 - 1 = 15 - 16

2 l x l = -1

1/2 ( 2 l x l ) = 1/2 (-1)

l x l = -1/2

NOT POSSIBLE! So the answer is the null set