Simplify and write in scientific notation.

Question

(9 X 10^-3)^2

A. 8.1 X 10^-5
B. 81 X 10^-4
C. 81 X 10^-3
D. 8.1 X 10^-6

?

Evaluate 1/2a^-4 b^2 for a = -2 and b = 4.

A. 2
B. 1/2
C. 3
D. 4

B

Answer 1

81 * 10*-6
= 8.1 * 10^-5

I have no idea. use parentheses or write it like this
1
-----------
2 a^-4b^2

or do you mean this?
(1/2) a^-4 b^2

or maybe
1
------------- b^2
2 a^-4

Answer 2

This one: (1/2) a^-4 b^2

Answer 3

that is
b^2
------------
2 a^4

4^2
--------
2 (-2)^4

16
-------
2(16)

1/2

Answer 4

(9x10⁻⁴)(8x10⁷)