This document discusses solving two-step equations. It provides examples of solving equations through undoing operations in reverse order based on the PEMDAS method. Students are shown how to solve equations, check their work, and apply equation solving to real-life word problems involving variables like the number of pickles a soccer player can eat or the price of plants at a fundraiser.

1. Chapter 7 Solving Equations and Inequalities Section 1: Solving Two-Step Equations January 5 th , 2009 Last Chapter of Quarter 2

2. Spray On Warm Up! Distributive Property (-5)(4x – 3) (7)(2x + 5) (3)(6m + 1)

3. Solving Two-Step equations There is a model method, but who cares about that. To SOLVE, find the value of a variable, a two-step equation, first undo addition or subtraction, then undo multiplication and division. In other words, to SOLVE, do PEMDAS backwards. (SADMEP)

4. Check Your Work 3n – 6 = 15 + 6 + 6 3n = 21 3 3 n = 7 Equation Addition Prop. of Equality Simplify Division Prop. of Equality Solve Now that we know n = 7, to check, we stick it back in to check.

5. Check Your Work 3( 7 ) – 6 = 15 21 - 6 = 15 15 = 15 Equation with variable. Simplify Solve, true statement. Now that we know n = 7, to check, we stick it back in to check.

6. Solve and Check Your Solution 15x + 3 = 48 T/4 – 10 = -6 9g + 11 = 2

7. The Dietary Soccer Player A soccer player wants to eat 700 calories at a meal that includes a Reuben sandwich and pickles. The sandwich has 464 calories, and the pickles have 7 calories each. Solve the equation 464 + 7f = 700 to find the number of pickles the soccer player can eat.

8. The Dietary Soccer Player A soccer player wants to eat 700 calories at a meal that includes a Reuben sandwich and pickles. The sandwich has 464 calories, and the pickles have 7 calories each. Suppose the soccer player drinks a 200 calorie sports drink with the meal. Create another equation that incorporates the drink to determine how many pickles the soccer player can now eat to stay within his diet.

9. Solve and Check Your Solution 15x + 3 = 48 T/4 – 10 = -6 9g + 11 = 2

10. Reminder About Equations and Negative Variables What is –x? -x is like saying (-1)x or –1 • x. Therefore, -x is the opposite of x. Solve: 5 – x = 17 + (-5) + (-5) 0 - x = 12 (-1) (-1) x = -12 Equation Addition Prop. of Equality Simplify Division Prop. of Equality Solution Now Check Your Answer!

11. Try These -a + 6 = 8 -9 – (y/7) = -12 13 – 6f = 31

12. Two Step Equations in Real Life Lynne saves $45 each week. She now has $180. She plans to save for a trip to Puerto Rico. To find how many weeks w she will take to save $900, solve $180 + $45w = $900. It will take Lynne 16 weeks from now, to save up 900 bucks.

13. Try This One Jacob bought four begonias in 6 inch pots and a $19 fern at a fund-raiser. He spent a total of $83. Solve the equation 4p + $19 = $83 to find the price p of each begonia. Each pot of begonias cost $16.

14. Assignment #52: Page 338: 1-31 All.