1. Course 1 2-3 Equations and Their Solutions Course 1 Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day

2. 29 16 9 Warm Up Evaluate each expression for x = 8. 1. 3x + 5 2. x + 8 3. 2x – 7 4. 8x  4 5. 7x – 1 6. x – 3 Course 1 2-3 Equations and Their Solutions 55 5

3. Problem of the Day Complete the magic square so that every row, column, and diagonal add up to the same total. Solving Subtraction Equations 10 7 4 92 86 12 5 Course 1 2-3 Equations and Their Solutions

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

5. equation solution Course 1 2-3 Equations and Their Solutions Vocabulary

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

7. Equations may contain variables. If a value for a variable makes an equation true, that value is a solution of the equation. Course 1 2-3 Equations and Their Solutions 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.

8. 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. Course 1 2-3 Equations and Their Solutions b — 447 = 1,203 Substitute 1,650 for b. 1,203 = 1,203 ? 1,650 — 447 = 1,203 ? 1,203 Subtract.

9. 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. Course 1 2-3 Equations and Their Solutions 27x = 1,485 Substitute 54 for x. 1,458 = 1,485 ? 27  54 = 1,485 ? 1,458 1,485 Multiply.

10. 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. Course 1 2-3 Equations and Their Solutions u + 56 = 139 Substitute 73 for u. 129 = 139 ? 73 + 56 = 139 ? Try This: Example 1A 129 139 Add.

11. 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. Course 1 2-3 Equations and Their Solutions 45  g = 3 Substitute 15 for g. 3 = 3 ? 45  15 = 3 ? Try This: Example 1B 3 3 Divide.

12. 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. Course 1 2-3 Equations and Their Solutions Substitute 19 for y 684 = 664 ? Multiply. 36  yd = in. 36  19 = 664 ? 36  y = 664

13. 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. Course 1 2-3 Equations and Their Solutions 12f = 84 Substitute 7 for f. 84 = 84 ? 12  7 = 84 ? Try This: Example 2 12  ft. = in. Multiply.

14. Determine whether the given value of the 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.) Course 1 2-3 Equations and Their Solutions