Equation Vocabulary

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

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

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

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

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.

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

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

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

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 each. She has $ How many CDs can she buy?

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!

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Practice Determine if the given values make the equation true x = 102 for x = x = 26 for x = 4 x + 46 = 214 for x = x = 35 for x = 26

More Practice  Which of the following values will make the equation true?  x=9, x=12, x=15, x=18  x + 3 = x – x = 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 – y = 7