### Study_guide_answers_answers_unit_1-1

```Coordinate Algebra
Practice
EOCT Answers
Unit 1
#1
A rectangle has a length of 12 m and a
width of 400 cm. What is the perimeter
of the rectangle?
A. 824 cm
B. 1600 cm
C. 2000 cm
D. 3200 cm
Unit 1
Step 1: Change 12 meters to centimeters
12 m
1
×
100 cm
1m
=
1200 cm
Step 2: Find perimeter using formula
P = 2L + 2W
1200 cm
P = 2(1200 cm) + 2(400 cm)
400 cm
P = 2400 cm + 800 cm
P = 3200 cm
Unit 1
#2
The tension caused by a wave moving along a string is found
mv 2
using the formula T =
. If m is the mass of the string in
L
grams, L is the length of the string in centimeters, and v is the
velocity of the wave in centimeters per second, what is the unit
of the tension of the string, T ?
2
m  grams ( g )
2
(cm)
 cm 
v 
 
2
 sec  (sec)
L  (cm)
2
2
(cm)
(g) 
2
2
mv
(sec)

T
(cm)
L
#2
2
2
Unit 1
g (cm)
(cm)
(g) 
2
2
2
g (cm) (cm)
(sec)
(sec)



T
2
(cm)
(sec)
1
(cm)
(cm)
2
1
g (cm)
1
g (cm) 1 g (cm)

T


2
2
1 
2
(sec)
(cm)
(sec) 1 (sec)
1
A. gram-centimeters per second squared
B. centimeters per second squared
C. grams per centimeter-second squared
D. centimeters squared per second
Unit 1
#3
The distance a car travels can be found using the
formula d = rt, where d is the distance, r is the rate
of speed, and t is time. How many miles does the
car travel, if it drives at a speed of 70 miles per hour
for ½ hour?
A. 35 miles
B. 70 miles
C. 105 miles
D. 140 miles
d = r t
70 miles 1 2 hour
d

hour
1
70 miles 0.5 hour
d

= 35 miles
hour
1
Unit 1 A certain population of bacteria has an average
growth rate of 0.02 bacteria per hour. The
#4
formula for the growth of the bacteria’s
population is A= P (2.71828)0.02t, where P0 is the
original population, and t is the time in hours.
If you begin with 200 bacteria, about how many
bacteria will there be after 100 hours?
0.02t
A= P(2.71828)
Answer
A= 200(2.71828)0.02100
1478
2
A= 200(2.71828)
A= 200(7.389046) = 1477.81
Unit 1
#5
The sum of the angle measures in a
triangle is 180°. Two angles of a
triangle measure 20° and 50°. What is
the measure of the third angle?
A.
B.
C.
D.
30°
70°
110°
160°
Third Angle = x
x + 20° + 50° = 180°
x + 70° = 180°
–70° –70°
x
= 110°
#6
A.
B.
C.
D.
Unit 1
Which equation shows P = 2l + 2w
when solved for w ?
2l
w
P
2l  P
w
2
P
w  2l 
2
P  2l
w
2
P = 2l + 2w
–2l
–2l
P – 2l =
P – 2l
=
2
P – 2l =
2
2w
2w
2
w
Bruce owns a business that produces widgets.
He must bring in more in revenue than he pays
out in costs in order to turn a profit.
#7
Unit 1
 It costs \$10 in labor and materials to make each of his widgets.
 His rent each month for his factory is \$4000.
 He sells each widget for \$25.
How many widgets does Bruce need to sell monthly to make a profit?
A.
B.
C.
D.
160
260
267
400
Revenue (in dollars)
from selling x widgets
R = 25x
Cost to make x widgets
C = 10x + 4000
Note: A profit occurs when enough widgets are
made and sold to break even. (i.e. R = C)
(Set up equation)
R = C
25x = 10x + 4000
#7
Bruce owns a business that produces widgets.
He must bring in more in revenue than he pays
out in costs in order to turn a profit.
Unit 1
 It costs \$10 in labor and materials to make each of his widgets.
 His rent each month for his factory is \$4000.
 He sells each widget for \$25.
How many widgets does Bruce need to sell monthly to make a profit?
A.
B.
C.
D.
160
260
267
400
(Set up equation)
Note: A minimum of
267 widgets must be sold
in order to make a profit.
25x = 10x + 4000
–10x –10x
15x =
4000
15x
15
x
4000
15
267
=
=
```