1.1 EXERCISE SET
In Exercises 1–14, write each English phrase as an algebraic expression. Let x represent the number.
1.
Five more than a number
X+5
3.
Four less than a number
X-4
5.
Four times a number
4X
7.
Ten more than twice a number
2X+10
9.
The difference of six and half of a number
6 – ½X
11.
Two less than the quotient of four and a number
4/X -2

13.
The quotient of three and the difference of five and a number
= 3/5-X
In Exercises 15–26, evaluate each algebraic expression for the given value or values of the variable(s).
15.
7 + 5x, for x = 10
7+5.10
7+50 = 57
17.
6x − y, for x = 3 and y = 8
6.3-8
18-8=10
19.
x2 + 3x, for
= 1 10/9

21. x2 − 6x + 3, for x = 7
49-42+3 = 10

23.
4 + 5(x − 7)3, for x = 9
4+5 (9.-7 ) ³
4+5 (2)³
4+5.8
4+40 = 44
25.
x2 − 3(x − y), for x = 8 and y = 2

X²-3X+3Y
8²-3 (8)+3(2)
64-24+6 = 46

expresses the relationship between Fahrenheit temperature, F, and Celsius temperature, C. In Exercises 95–96, use the formula to convert the given Fahrenheit temperature to its equivalent temperature on the Celsius scale.
95.
50°F = 10
C = ( 50-32) = 5/9
C = (12 ) 5/9
C+ 10

A football was kicked vertically upward from a height of 4 feet with an initial speed of 60 feet per second. The formula
H= 4+60t -16t² describes the ball’s height above the ground, h, in feet, t seconds after it was kicked. Use this formula to solve Exercises 97–98.
97.
What was the ball’s height 2 seconds after it was kicked?
60 ft

Section 1.2
In Exercises 1–12, find each absolute value.
1.
|−7|
= 7
3.
|4|
=4

5.
|−7.6|
= 7 .6
7. π/2 = π/2

9. | -√2|= √2

11. - |- 2/5 | = - 2/5

In Exercises 13–28, add as indicated.
13.
−3 + (−8)
= 11
15.
−14 + 10 = -4
17.
−6.8 + 2.3 = -4.5

19. 11/5 + (-3/5)

21. -2/9 –