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Lesson 1-11/1-12. Solving Equations. 1-11. Solving Equations. Course 3. Remember : An equation uses an equal sign to show two expressions are equal. In order for both sides to be balanced both sides need to be equal. Examples of equations include:. 3 + 8 = 11. 24 = 31 – 7. 1-11.
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Lesson 1-11/1-12 Solving Equations
1-11 Solving Equations Course 3 Remember : An equation uses an equal sign to show two expressions are equal. In order for both sides to be balanced both sides need to be equal. Examples of equations include: 3 + 8 = 11 24 = 31 – 7
1-11 Solving Equations Course 3 In this lesson you will be asked to solve equations. When solving equations find the value of the variable that makes the equation true. Remember: This value of the variable is called the solution, or the answer to the equation
1-11 Solving Equations Course 3 Let’s look at some equations that deal with adding a number to the variable. What are the solutions? • 5 + X = 17 • N + 34 = 54 • 3. A + 13 = 36 How do you know the value of the variables you chose are right?
1-11 Solving Equations Course 3 Let’s try to create a general rule that will help us solve equations that deal with addition. 1. Think of a rule we can follow for solving for x in the equation 10 + x = 23. 2. Will your rule work for x + 15 = 32? 3. How about 12 + x = 15?
1-11 Solving Equations Course 3 How about when we subtract a number from the variable such as: X – 3 = 16 Can we write a rule for solving for x when subtracting a number? Does your rule work for X – 12 = 15?
1-11 Solving Equations Course 3 What about multiplying a number by a variable. How might we solve these? 3X = 15 Can you write a rule for solving for x here? What do you think our rule might be for solving equations that deal with division like X ÷ 5 = 10
Can we summarize are rules down to just one that will work for solving all equations? X + 25 = 45 X ÷ 5 = 8 X - 25 = 12 4X = 44
Solving Equations by Adding or Subtracting 1-11 Course 3 Inverse operations are opposites, which means they “undo” each other. To undo addition, subtract To undo subtraction, add To undo multiplication, divide To undo division, multiply Course 3
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