1 Math 090 Exam 3 Review – Chapter 4 Remember that material from earlier exams may be on this exam also – your exams will build on each other! Section 4.1 Integers: Opposites, Absolute Value, and Inequalities Negative numbers are located to the left of 0 on the number line Positive numbers are located to the right of 0 on the number line Opposite – the opposite of a number is the number that is the same distance from the number and zero on the number line but on the opposite side of 0 Absolute Value – the distance between zero and the number on the number line. The distance is always positive or 0. To find the absolute value: if the number is positive or 0, write the number. If the number is negative, write its opposite. The absolute value of 0 is 0. Whole numbers are 0, 1, 2, 3, …. Integers are the whole numbers and their opposites: … 3, 2, 1, 0, 1, 2, 3… When comparing two integers, remember that the number farthest to the right on the number line is the greater number. Simplify: 1. ( 196) 2. [ ( 47)] 3. Brad’s doctor recommended to him that he exercise for a certain period of time five days a week. During the first week, on the first two days he exercised 18 minutes more than he needed to. On the next two days he exercised 27 minutes less than he was supposed to, and on the last day, he exercised 14 minutes more than he was supposed to. Looking at the week as a whole, how many minutes more or less than the doctor recommended did he exercise? Express your answer as a signed number. Find the absolute value: 4. 5. 467 56 27 10 2 6. Evaluate: 46 32 7. True or False? x 7 has one solution, x 7 True or False: 8. 26 15 9. ((11)) (((4))) Section 4.2 Adding Integers Add: 10. 57 168 11. 765 (258) 12. 25, 689 (25, 689) 13. 174 (506) 492 Section 4.3 Subtracting Integers 14. 65 14 (18) 5 15. 16 21 14 6 (5) 16. True of false, 42 76 42 76 3 Section 4.4 Adding and Subtracting Polynomials (Integers) Simplify: 17. 35 x 45 x (22 x) 18. 9x 19. Subtract 8 x 2 9 x 12 from 4 x 2 3 x 9 20. Find the difference between 8 x 2 9 x 12 and 4 x 2 3 x 9 2 15 x 17 5 x 2 21 14 x Section 4.5 Multiplying and dividing Integers Multiplication and Division: + times + = + times = + + times = times + = Squaring a number means multiplying a number by itself (ex. 32 = 3·3=9) 32 (3) 2 2 *NOTE THAT: 3 (3 3) 9 (the opposite of 3 3 which is 9) (3) 2 (3) (3) 9 (here a negative times a negative equals a positive) ALSO NOTE THAT A NEGATIVE TO AN EVEN POWER IS POSITIVE AND THAT A NEGATIVE TO AN ODD POWER IS NEGATIVE. 4 Simplify: 21. 92 12 2 3 3 32 22. 5 3 110 3 6 22 2 23. True or false, 2 24. True or false, 5(6) 5 (6) Section 4.6 Multiplying and dividing Polynomials (Integers) Rules for variables with exponents: Multiplying: add exponents ex. ( x 2 ) ( x3 ) x 23 x5 Dividing: subtract exponents ex. x5 x 5 2 x 3 2 x Power to a power: multiply exponents ex. x 2 3 x 23 x6 Remember that any number (other than 0) to the zero power = 1 ex. x 0 1 for x ≠ 0 Simplify: 25. 4 x 3 x 2 12 y 26. 12 x 2 y 3 3 y 8 5 x 4 y 4 5 27. 3x 512 x 8 28. 4 x 10 9 x 5 29. 2(6 x 4) (3x 2) 30. ( x 5) 6(2 x 7) Divide: 31. 45 x 2 y 20 x 5x 32. 27 x3 y 4 15 x 2 y 3 3x 2 y 3x 2 y 6 Section 4.7 Order of Operations and Average (Integers) Reminder: You must calculate problems in this order to get the right answer: Please Excuse My Dear Aunt Sally Or: Parentheses Exponents Multiplication and Division (left to right) Addition and Subtraction (left to right) Simplify: 33. 3 42 6 2 7 (9) 3 34. 14 36 4 2 7 22 3 2 2 35. 32 10 2 3 10 3 4 36. What is the result of the product of 12 and the difference of 23 and 45 ? 37. What is the result when 10 is subtracted from the quotient of 16 and 4? Find the average: 38. Find the average of: 14, 6, 5, 3, and 15 39. Find the average of: 35, 10, 46, and 13 7 Section 4.8 Evaluating Algebraic Expressions and Formulas (Integers) Evaluate: 40. 41. x y z 2 ( x) 2 2 3 x 2 (4) x + xy y for x 5, y 6, z 4 for x 5 y 4 Section 4.9 Solving Equations (Integers) 42. 5r 16 51 43. ( x 25) 3 x 5 6 x 44. 16x 20 14x 13 5x 34 45. 3p 6 18 4 8 Answers to Math 090 Exam 3 Review 1. 196 24. False 2. 47 25. 12 x3 48 xy 3. 4 minutes (He exercised 4 minutes 26. 36 x 2 y11 60 x6 y 7 less than the doctor recommended.) 27. 36 x 2 36 x 40 4. 467 28. 36 x 2 110 x 50 5. 19 29. 9x 6 6. 14 30. 13x 47 7. False, another solutions is x = 7 31. 9 xy 4 8. False 32. 9 xy 3 5 y 2 1 9. False 33. 10. 111 34. 7 11. 1023 35. 12. 0 36. 264 13. 188 37. 6 14. 66 38. 5 15. 8 39. 21 16. False 40. 17. 32x 41. 22 18. 4 x 2 x 4 42. r=7 2 19. 12 x 6 x 3 43. x = 10 20. 12 x 2 12 x 3 44. x = 9 21. 19 45. p = 16 22. 50 23. False 9 22 11