Page 265 - Basic College Mathematics with Early Integers

242 C HAPTE R 3 I FRACTIONS

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91. Two positive numbers, a and b, are graphed below. 92. Study Exercise 91.Without calculating, can be the
Where should the graph of their average lie? 1 8 3
average of and ? Explain why or why not.
2 9
a b

For Exercises 93–98, answer true or false for each statement.

93. It is possible for the average of two numbers to be 94. It is possible for the average of two numbers to be
greater than both numbers. less than both numbers.

95. The sum of two negative fractions is always a 96. The sum of a negative fraction and a positive
negative number. fraction is always a positive number.

97. It is possible for the sum of two fractions to be a 98. It is possible for the difference of two fractions to
whole number. be a whole number.

1
99. What operation should be performed first to 100. A student is to evaluate x - y when x = and
5
simplify 1
y =- . This student is asking you if he should
1 5 2 4 2 7 1 1
# - a + b ? evaluate - . What do you tell this student and
5 2 3 5 5 7
why?
Explain your answer.

Each expression contains one addition, one subtraction, one multiplication, and one division.Write the operations in the
order that they should be performed. Do not actually simplify. See the Concept Check in this section.

10 5
101. [9 + 3(4 - 2)] , 102. [30 - 4(3 + 2)] ,
21 2

1 2 4 1 1 5 1 1 1 9
103. , a ba b - + 104. a - b # + ,
3 3 5 4 2 6 3 3 2 8

3 4
Evaluate each expression if x = and y =- .
4 7 9
2 + x 14
2
105. 106. 4x + y 107. x + 7y 108.
y x + y

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