1.
Express 0.0000421 in scientific notation.
A.
4.21 × 10
-4
B.
4.21 × 10
-5
C.
4.21 × 10
-9
D.
4.21 × 10
-6
Hint
2.
Simplify (7
a
4
b
) (8
a
7
b
6
).
A.
56
a
11
b
7
B.
56
a
28
b
6
C.
15
a
28
b
6
D.
15
a
11
b
7
Hint
3.
Solve the equation
x
2
= 0.81.
A.
none of these is correct
B.
x
= 0.9 or
x
= -0.9
C.
x
= 0.9 only
D.
x
= -0.9 only
Hint
4.
Simplify
.
A.
B.
C.
D.
Hint
5.
Use the following table to find the population of bacteria in hour
n
.
A.
30,000
6
n
B.
180,000
n
C.
6 × 30,000
n
D.
30,000 × 6
6
Hint
6.
Which equation represents exponential growth?
A.
y
= 250 ·
x
B.
y
= 250 × 4
x
C.
y
= 250 × 0.25
x
D.
y
= 250 × 0.4
c
Hint