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Example 4-1a Evaluate simple algebraic expressions Objective

Example 4-1a Variable A symbol, usually a letter, used to represent a number Vocabulary

Example 4-1a Algebraic Expression An expression that contains a variable, a number, and at least 1 operation X + 2 Vocabulary

Example 4-1a Algebra A branch of math that involves expressions with variables Vocabulary

Example 4-1a Term Each part of an algebraic expression that is separated with a plus or minus sign 8x + y – 3 Terms are 8x, y, and -3 Vocabulary

Example 4-1a Coefficient The numerical factor of a term that contains a variable 8x + y – 3 8 is the coefficient of 8x 1 is the coefficient of y Vocabulary

Example 4-1a Constant A term that does not contain a variable 8x + y – 3 -3 is the constant Vocabulary

Lesson 4 Contents Example 1Evaluate an Expression Example 2Evaluate Expressions Example 3Evaluate Expressions Example 4Evaluate Expressions Example 5Use an Expression to Solve a Problem

Example 4-1a Answer: 2 Evaluate 2 1/5 Write expressiont - 4 Replace t with Subtract 6 - 4

Example 4-1b Evaluate 1/5 Answer: 11

Example 4-2a Evaluate 5(7) + 3(9) /5 5x + 3y Write expression Replace x with 7 Replace y with 9 P E MD AS Multiply from left to right Bring down + Multiply 3(9) Multiply 5(7) Follow Order of Operations Rules

Example 4-2a Answer: 62 Evaluate /5 Add

Example 4-2b Evaluate 2/5 Answer: 24

Example 4-3a Evaluate 4 3/5 Write expression rs 4 Replace r with 7 77(12) Replace s with 12 Bring down 4 P E MD AS Follow Order of Operation Rules Remember: A fraction bar can act as an enclosure

Example 4-3a Answer: 21 Evaluate /5 rs 4 Multiply 7(12) 7(12) A fraction bar means division Bring down 4 Divide 84 by 4

Example 4-3b Evaluate 3/5 Answer: 12

Example 4-4a Evaluate /5 Write expression 5 + a 2 Replace a with 5 P E MD AS Do exponents first Bring down Find 5 2 Bring down 5 + Follow Order of Operations Rules

Example 4-4a Answer: 30 Evaluate /5 Add

Example 4-4b Evaluate 4/5 Answer: 15

Example 4-5a PHYSICS The final speed of a falling object is found by using the expression v + 9.8t, where v is the speed when you begin timing and t is the length of time the object falls. Find the final speed when the object starts falling at 3 meters per second and falls for 2 seconds. v + 9.8t Write equation given (2) 5/5 Replace v which is speed with 3 Bring down Replace t which is time with 2

Example 4-5a PHYSICS The final speed of a falling object is found by using the expression v + 9.8t, where v is the speed when you begin timing and t is the length of time the object falls. Find the final speed when the object starts falling at 3 meters per second and falls for 2 seconds. Answer: 22.6 meters per second (2) /5 P E MD AS Multiply 9.8(2) Multiply first Bring down 3 + Add Label Follow Order of Operations Rules

Example 4-5b BOWLING David is going bowling with a group of friends. His cost for bowling can be described by the formula g, where g is the number of games David bowls. Find the total cost of bowling if David bowls 3 games. * 5/5 Answer: $9.25

End of Lesson 4 Assignment Lesson 1:4 Algebra: Variables and Expressions All