Dynamic Activity

Using Algebraic Equations

Lesson Vocabulary

• equation
• open sentence
• solution of an equation

Problem 1 Classifying Equations

Is the equation true, false, or open? Explain.

1. 24 + 18 = 20 + 22 True, because both expressions equal 42
2. 7 · 8 = 54 7 middle dot 8 equals 54  False, because 7 · 8 = 56  and  56 ≠ 54 7 middle dot 8 equals 56 , and , 56 not equal to 54
3. 2 x − 14 = 54 2 x minus 14 equals 54  Open, because there is a variable

✓ Got It?

1. Is the equation true, false, or open? Explain.
   1. 3 y + 6 = 5 y − 8 3 y plus 6 equals 5 y minus 8
   2. 16 − 7 = 4 + 5 16 minus 7 equals 4 plus 5
   3. 32 ÷ 8 = 2 · 3 32 divides 8 equals 2 middle dot 3