1. Bell Ringer
Darius saw a shirt that was on sale for 20% off. The original price of the shirt was $28. If tax was 9%, how much did Darius pay for the shirt?
Discount: $28 • .20 = $5.60 off
Sale Price of Shirt: $28 – $5.60 = $22.40
Tax: $22.40 • .09 = $2.016 (Tax)
Final Cost: $ $2.016 = $24.416
$24.42

2. Homework
1. x = 2 2. x = 5 3. x = 7 4. x = 4 5. x = 0 6. x = 3 7. x = 9 8. x = 4/3 or 1 1/3 or 1.33

3. Selected Problems
#3 -5x – 6 = -7x x = -7x x +7x 2x = 14 x = 7 #5
2(x + 3) = -2x + 6
2x + 6 = -2x + 6
– – 6
2x = -2x
+2x +2x
4x = 0
x = 0

4. Selected Problems
#7 2(2x – 1) = 3x + 7 4x – 2 = 3x x = 3x x -3x x = 9 #8
x + 5 = -2x + 9
– – 5
x = -2x + 4
+2x +2x
3x = 4
x = 4/3 or
1 1/3 or
1.33

5. Manipulating and Solving Equations
XEI 601: Manipulate expressions and equations

6. Manipulating Equations
Like we saw last Friday, we often have to simplify equations before we solve them.
We have to distribute, combine like terms, and move terms before solving.
We will continue to work on those skills today.

7. Combining Like Terms
7x + 8 = 5x + 12 – 8 – 8 7x = 5x + 4 – 5x – 5x 2x = 4 x = 2
Move all of the numbers to the right.
Move all of the variables to the left.
Solve for X

8. Combining Like Terms
4x – 7 + 2x = -2x x + 2x = -2x x = -2x x +2x 8x = 24 x = 3

9. Distributive Property
3(2x – 4) = 2x 6x – 12 = 2x x = 2x + 12 – 2x – 2x 4x = 12 x = 3
Distribute
Move
Solve

10. Distributive Property
-4(2x – 5) = -2(3x + 1) -8x + 20 = -6x – 2 – 20 – 20 -8x = -6x – 22 +6x +6x -2x = -22 x = 11

11. What is wrong with me?
-3(x – 2) = -2x x – 6 = -2x x = –2x x +2x -x = 10 x = 10

12. What is wrong with me?
-5x – 5 + 2x = -2x x + 2x = -2x x = -2x x = 5 x = 1