1. Equation Vocabulary

2. Warm-Up  2(1 + 6x)  Find the surface area of a cube where the side (s) is 5 cm. Surface area= 6s 2

3. Important Vocabulary!!  Equation   A math sentence that contains an equal sign.   It consists of 2 expressions, one on each side of the equal sign.  Examples: 5x + 3 = 18; x ÷ 10 = 12

4. Important Vocabulary!!  Inverse Operations   Two operations that are opposites so they cancel each other out.   They “undo” each other!

5. What are the inverse operations?  Addition and subtraction  Multiplication and division  How does it work?  x + 5 - 5 - 5  All you would be left with is x because the inverse operations cancel each other out.

6. Important Vocabulary!!  Properties of Equality   When both sides of an equation have the same number added, subtracted, multiplied, or divided, the remaining expressions are still equal.

7. How do the properties of equality work?  x + 3 = 9  You can use the inverse operation of addition (subtraction) on both sides.  x + 3 = 9 -3 -3 -3 -3  If you take away the same number from both sides, then they would still be equal.

8. Important Vocabulary!!  Solution   The set of all values or a single value that make an equation true.  How do you write solutions?  You put the variable from the equation, then an equal sign, and finally put what the variable equals.  Example: x = 5; y = 18

9. Important Vocabulary!!  Reciprocal   When you flip the numerator and denominator of a fraction  Examples: 3/4 to 4/3 and 5/6 to 6/5

10. Warm-Up  A bottle of puppy medicine says to give 3 mL for every pound of body weight. How much would you give a 15 lb. puppy?  Amy wants to buy some CD’s that are 11.99 each. She has $74.90. How many CDs can she buy?

11. Substituting into Equations  You will just replace the variable with the given value  Then you will determine whether or not it is a solution to the equation  If it is a solution, then both sides of the equation will be equal!

12. Learnzillion  http://learnzillion.com/lessons/2514- understand-that-equations-have-one- solution-using-a-pan-balance http://learnzillion.com/lessons/2514- understand-that-equations-have-one- solution-using-a-pan-balance http://learnzillion.com/lessons/2514- understand-that-equations-have-one- solution-using-a-pan-balance

13. Practice Determine if the given values make the equation true. 86 + x = 102 for x = 16 18 + x = 26 for x = 4 x + 46 = 214 for x = 168 9 + x = 35 for x = 26

14. More Practice  Which of the following values will make the equation true?  x=9, x=12, x=15, x=18  x + 3 = x – 6 6 3 x = 15

15. Just one more…  Which of the following values will make the equation true?  y=4, y=5, y=6, y=7  3y + 4 = 4y – 8 5 4 y = 7