Chapter 1: Expressions, Equations & Inequalities Section 3: Algebraic Expressions Name ___________________ Date ____________ Period ________ Algebraic Expressions *If you are absent the day we complete this handout together in class it is your responsibility to fill it in; please borrow from a friend to get the notes you missed! Vocabulary o Variable – A letter used to represent a number Ex. x = 3 “x” is the variable and the number it represents is 3 Ex. x + 5 = 7 “x” is the variable and the number it represents is 2 o Algebraic Expression – contains one or more variables (letters) Ex. x – 10 Ex. 13 + m Ex. 10n Ex. a + b o Numerical Expression – Contains numbers, but NOT variables (letters) Ex. 8 – 5 Ex. 3(4 + 1) Examples o Is each expression algebraic or numerical? 7+2 4m + 6 2(5 – 4) Chapter 1: Expressions, Equations & Inequalities Section 3: Algebraic Expressions o Key Word Less than More than Sum Difference Product Quotient Operation ( +, −, ×, ÷ ) o What is an algebraic expression for each phrase? The difference of a number, x, and ½. 12 less than a number, p. ****Note that with subtraction the wording determines the order! The product of 9 and a number t. The sum of a number, m, and 7.1. The quotient of 207 and a number, n. The sum of the product of a number k and 4, and a number m. Nine more than the product of a number, x, and two. The quotient of the sum of 2 and a number, b, and 3. Jordan currently has $102 and gets and additional $12 per day for doing chores. Chapter 1: Expressions, Equations & Inequalities Section 3: Algebraic Expressions o Use words to describe each algebraic expression 6n x 2 p–1 6n – 1 o Evaluate: g + 2g – g -1 given than g = 2 4x + 7y +3x – 2y + 2x given that x = -3 and y = 2 -h2 – (3h – 5j) + 4j given that h = -1 and j = -4 4(2w – x) – 3(2w – x) given that w = -5 and n = -2 m2 + 100 given than m = √11 Chapter 1: Expressions, Equations & Inequalities Section 3: Algebraic Expressions Combining “Like Terms” Like Term – Must have the same variable (letter) AND the same exponent on the variable; the coefficient (number in front) does not matter When terms are “like” they can be combined by keeping the “term” and doing the math on the coefficient It is important to remember that “the sign before it goes with it” o Ex. -4xy2 is a negative (or subtraction) term o Ex. 6mn3 is a positive (or addition) term o Example #1: Simplify: 7m2 + 3n -5m2 + 4m 7m2 and -5m2 are “like terms” because they both contain the variable “m” and both have an exponent of “2”; 5m2 is negative since “the sign before it goes with it” 7m2 – 5m2 = 2m2 this is combining like terms! Since 3n and 4m do not have any terms that are “like” they stay as is and the final answer is 2m2 + 4m + 3n o Are the terms “like” or “not like”? If “not like,” explain why. 1. 2. 3. 4. 5. 8x3 and 8x2 7xyz and 10xyz -3mn and -3m2n 4p3q2r and 14p3q2r h7k and 13hk7 Chapter 1: Expressions, Equations & Inequalities Section 3: Algebraic Expressions o Simplify by combining Like Terms: 1. 3x2 + 5x2 2. 4xy3 – x3y 3. -6x4 + 11x4 4. 2x2y4 – 7x2y4 5. 4x – 1 + 5x3 + 7x 6. (x2 – 2x + 3) + (3x2 – 2x – 1) 7. (5x3 – x2 + 6x – 3) + (-2x3 + 4x2 – 2x + 1) 8. (x3 – 3x2 + 5x) – (7x3 + 5x2 – 12) 9. (5r3 + 8) + (6r3 + 3) 10. (x2 – 2) – (3x + 5) 11. –(2a + b) – 2(-a – b) 12. m(3 – n) + n(m + 7)