Presentation on theme: "2-5 Reasoning in Algebra and Geometry"— Presentation transcript:
1 2-5 Reasoning in Algebra and Geometry Objective:To connect reasoning in algebra and geometryEssential Understanding: Algebraic properties of equality are used in geometry. They will help you solve problems and justify each step you take.
4 Example: Solve for x. Give reason for each step. You use deductive reasoning when you solve an equation. You can justify each step with a postulate, a property, or a definition.Example: Solve for x. Give reason for each step.3(2x + 1) + 2(2x +1) + 7 = 42 – 5xGiven6x x = 42 – 5xDistributive Property10x + 12 = 42 – 5xCombine Like terms15x + 12 = 42Addition Property of Equality15x = 30Subtraction Property of Equalityx = 2Division Property of Equality
5 What is the value of x? Justify each step. x = 2x - 75Definition of an angle bisector.x + 75 = 2xAddition Property of Equality.75 = 2x - xSubtraction Property of Equality.x = 75Distributive Property
6 Properties of Congruence: Reflexive PropertySymmetric PropertyTransitive Property
7 p. 117: 5-11 odd [write both columns in each problem] Page 115a. Symmetric Propertyb. Distributive Propertyc. Multiplication Propertyd. Reflexive Propertyp. 117: 5-11 odd [write both columns in each problem]