Solve Multi-Step Equations POWER to the brain. Solving Equations Solving and equation to determine the “unknown” (the variable) is simply working backward by applying the inverse operation of how the equation was originally constructed. Two-Step Equation (from yesterday) n – 8 = -5 3 Now, it’s changed into a Multi-Step Equation 2n – 8 = -6 3 Practice Problem 3n + 6 = -6 5 Simplifying Equations Before an equation can be solved, the equation must FIRST BE SIMPLIFIED. A simplified equation has: • applied the distributive property if applicable • all terms are combined • the unknown variable is only on one side of the equal sign Remember solving an equation is a balancing act What you do to one side you have to do to the other!! Combining Like Terms First… 7 x 3x 8 24 Practice Problem 5x + 3 – 7x – 4 = 15 Practice 1. 5a – 7 + 3a = 17 2. 9b + 6 – 5b = 18 3. -5c – 10 – 5c – 2 = 8 4. 15n + 16n + 4n = 140 Simplify By Using the Distributive Property Distributive Property – Multiply what is on the outside of parentheses by everything in the parentheses. a(b + c) = ab + ac OR a(b – c) = ab – ac Example 1: -3(x + 5) -3x – 15 Example 2: -7(2a – 4) -14a + 28 Practice Problem -2(n - 5) = -2 Simplify and Solve Equations Example: 3(x – 2) + 4x = 8 SECOND: Combine like terms. Now it’s a regular 2-step equation. FIRST - Use the Distributive Property to get rid of the parentheses. Simplify and Solve Equations Example: 3x + 2(2x – 1) = 33 1.Use Distributive Property 2. Combine Like terms 3. Use Inverse Operations Practice 1. 4(x + 1) + 5 = 13 2. 5(y + 2) – y = -26 3. -9x + 6(2x + 8) = 96 4. 7y – 2(8y + 1) = 16