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Equations and Their Solutions. 1-10. Course 2. Warm Up. Problem of the Day. Lesson Presentation. Equations and Their Solutions. 1-10. Course 2. I can determine whether a number is a solution of an equation. Solving Equations by Adding or Subtracting. 1-10. 100. = 50. 2. Course 3.
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Equations and Their Solutions 1-10 Course 2 Warm Up Problem of the Day Lesson Presentation
Equations and Their Solutions 1-10 Course 2 I can determine whether a number is a solution of an equation.
Solving Equations by Adding or Subtracting 1-10 100 = 50 2 Course 3 An equation is a mathematical sentence that uses an equal sign to show that two expressions have the same value. All of these are equations. 3 + 8 = 11 r + 6 = 14 24 = x – 7 To solve an equation that contains a variable, find the value of the variable that makes the equation true. This value of the variable is called the solution, or the answer to the equation. Course 3
Solving Equations by Adding or Subtracting 1-10 Course 3 Think about a scale. How does it stay balanced? What happens if you take away objects from one side of the scale? How do you balance it back out? What about if you add objects?
Solving Equations by Adding or Subtracting 1-10 Course 3 An equation works the same way as a scale. It has to be balanced. This means both sides have to be equal.
1-10 Solving Equations by Adding or Subtracting Course 3 Find the missing number… • 5 + x = 17 • x – 34 = 12 • 3. a + 3 = 8 How do you know for sure the variable is what you say it is?
Equations and Their Solutions 1-10 Course 2 Here is an example: Ella has 22 CDs. This is 9 more than her friend Kay has. This situation can be written as an equation. Remember an equation is a mathematical Statement that two expressions are equal in value. Number of CDs Ella has 22 is equal to = 9 more than Kay has j + 9 Left expression Right expression
Equations and Their Solutions 1-10 ? 26 + 9 = 17 ? 35 = 17 Course 2 You’ll be asked to determine whether a value is a solution or not. Determine whether the given value of the variable is a solution of t + 9= 17. 26 t + 9= 17 Substitute 26 for t. 26 is not a solution of t + 9 = 17.
Equations and Their Solutions 1-10 ? 8 + 9 = 17 ? 17 = 17 Course 2 Additional Example 1B: Determining Whether a Number is a Solution of an Equation Determine whether the given value of the variable is a solution of t + 9= 17. 8 t + 9= 17 Substitute 8 for t. 8 is a solution of t + 9 = 17.
Equations and Their Solutions 1-10 Course 2 Insert Lesson Title Here Lesson Quiz Determine whether the given value of the variable is a solution of 5 + x = 47. 1.x = 42 2.x = 52 Determine whether the given value of the variable is a solution of57 – y = 18. 3.y = 75 4.y = 39 5. Kwan has 14 marbles. This is 7 more than Drue has. Does Drue have 21 or 7 marbles? yes no no yes 7