1. Course 1 2-4 Equations and Their Solutions Course 1 2-4 Equations and Their Solutions Course 1 Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day

2. Course 1 2-4 Equations and Their Solutions 2916 9 Warm Up Evaluate each expression for x = 8. 1. 3x + 52. x + 8 3. 2x – 74. 8x  4 5. 7x – 16. x – 3 55 5

3. Course 1 2-4 Equations and Their Solutions Learn to determine whether a number is a solution of an equation.

4. Course 1 2-4 Equations and Their Solutions equation solution

5. Course 1 2-4 Equations and Their Solutions An equation is a mathematical statement that two quantities are equal. You can think of a correct equation as a balanced scale. 3 + 2 5

6. Course 1 2-4 Equations and Their Solutions Equations may contain variables. If a value for a variable makes an equation true, that value is a solution of the equation. 12 + 15 27 s + 15 = 27 s = 12s = 10 10 + 15 27 s = 12 is a solution because 12 + 15 = 27. s = 10 is not a solution because 10 + 15  27.

7. Course 1 2-4 Equations and Their Solutions Determine whether the given value of the variable is a solution. Additional Example 1A: Determining Solutions of Equations b — 447 = 1,203 for b = 1,650 Because 1,203 = 1,203, 1,650 is a solution to b — 447 = 1,203. b — 447 = 1,203 Substitute 1,650 for b. 1,203 = 1,203 ? 1,650 — 447 = 1,203 ? 1,203 Subtract.

8. Course 1 2-4 Equations and Their Solutions Determine whether the given value of the variable is a solution. Additional Example 1B: Determining Solutions of Equations 27x = 1,485 for x = 54 Because 1,458  1,485, 54 is not a solution to 27x = 1,485. 27x = 1,485 Substitute 54 for x. 1,458 = 1,485 ? 27  54 = 1,485 ? 1,458 1,485 Multiply.

9. Course 1 2-4 Equations and Their Solutions

10. Course 1 2-4 Equations and Their Solutions Determine whether the given value of the variable is a solution. u + 56 = 139 for u = 73 Because 129  139, 73 is not a solution to u + 56 = 139. u + 56 = 139 Substitute 73 for u. 129 = 139 ? 73 + 56 = 139 ? Try this: Example 1A 129 139 Add.

11. Course 1 2-4 Equations and Their Solutions Determine whether the given value of the variable is a solution. 45  g = 3 for g = 15 Because 3 = 3, 15 is a solution to 45  g = 3. 45  g = 3 Substitute 15 for g. 3 = 3 ? 45  15 = 3 ? Try this: Example 1B 3 3 Divide.

12. Course 1 2-4 Equations and Their Solutions Paulo says that his yard is 19 yards long. Jamie says that Paulo’s yard is 664 inches long. Determine if these two measurements are equal. Additional Example 2 Because 684  664, 19 yards are not equal to 664 inches. Substitute. 684 = 664 ? Multiply. 36  yd = in. 36  19 = 664 ?

13. Course 1 2-4 Equations and Their Solutions Anna says that the table is 7 feet long. John says that the table is 84 inches long. Determine if these two measurements are equal. Because 84 = 84, 7 feet is equal to 84 inches. Substitute. 84 = 84 ? 12  7 = 84 ? Try this: Example 2 12  ft = in. Multiply.

14. Course 1 2-4 Equations and Their Solutions

15. Course 1 2-4 Equations and Their Solutions Determine whether the given value of each variable is a solution. 1. 85 = 13x for x = 5 2. w + 38 = 210 for w = 172 3. 8y = 88 for y = 11 4. 16 = w  6 for w = 98 Lesson Quiz no yes no 5. The local pizza shop charged Kylee $172 for 21 medium pizzas. The price of a medium pizza is $8. Determine if Kylee paid the correct amount of money. (Hint: $8 pizzas = total cost.)

16. Course 1 2-4 Equations and Their Solutions