38. Reasoning Savannah looks at the table shown and says the equation y = x − 6 y equals x minus 6  represents the pattern. Mary says y = x + ( − 6 ) y equals x plus open negative 6 close  represents the pattern. Who is correct? Explain.

    x	y
    0	− 6 negative 6
    1	− 5 negative 5
    2	− 4 negative 4
    3	− 3 negative 3

39. Open-Ended Think of a real-world pattern. Describe the pattern using words and an equation with two variables. Define the variables.

    C Challenge

40. Temperature Suppose the temperature starts at 60°F and rises 2°F every 45 min. Use a table, an equation, and a graph to describe the relationship between the amount of time that has passed in hours and the temperature.
41. Use a table, a graph, and an equation to represent the ordered pairs ( 2 , − 5.5 ) , ( − 3 , − 0.5 ) , ( 1 , − 4.5 ) , ( 0 , − 3.5 ) , ( − 3.5 , 0 ) , open 2 comma negative 5.5 close comma open negative 3 comma negative 0.5 close comma open 1 comma negative 4.5 close comma open 0 comma negative 3.5 close comma open negative 3.5 comma 0 close comma  and ( − 1 , − 2.5 ) . open negative 1 comma negative 2.5 close .

Standardized Test Prep

SAT/ACT

42. Use the graph. What is the total price for 4 bags of seeds?

    
    Image Long Description

    1. $.50
    2. $2.00
    3. $4.00
    4. $8.00
43. What is the simplified form of the expression − 5 ( n − 2 ) ? negative 5 open n minus 2 close question mark
    6. − 7 n negative 7 n
    7. − 5 n − 2 negative 5 n minus 2
    8. − 5 n + 10 negative 5 n plus 10
    9. n + 10
44. If a = 3 and b = − 2 , b equals negative 2 comma  what does − 2 b − a negative 2 b minus eh  equal?
    1. − 9 negative 9
    2. − 7 negative 7
    3. − 1 negative 1
    4. 1
45. What is the value of − 3 4 ? negative , 3 to the fourth , question mark
    6. − 81 negative 81
    7. − 12 negative 12
    8. 12
    9. 81

Mixed Review

See Lesson 1-8.

Tell whether the given number is a solution of each equation.

46. 3x + 7 = 10; 0
47. 80 = 4a; 20
48. 10 = − 5 t ; − 2 10 equals negative 5 t semicolon negative 2

See Lesson 1-4.

Give an example that illustrates each property.

49. Commutative Property of Addition
50. Associative Property of Multiplication
51. Identity Property of Multiplication
52. Zero Property of Addition

See Lesson 1-5.

Get Ready! To prepare for Lesson 2-1, do Exercises 53–60.

Find each sum or difference.

53. 12 + ( − 3 ) 12 plus open negative 3 close
54. − 7 + 4 negative 7 plus 4
55. − 8 + ( − 6 ) negative 8 plus open negative 6 close
56. − 42 + 15 negative 42 plus 15
57. 32 − ( − 8 ) 32 minus open negative 8 close
58. − 18 − 12 negative 18 minus 12
59. − 15 − ( − 14 ) negative 15 minus open negative 14 close
60. − 76 − 5 negative 76 minus 5

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