Question

#1 What is the value of the expression 7–3? Answers: A. –21 B. - 1/343 C.1/343 D. 343  #2What is the value of the expression 1/5^-5? Answers: A. 1/3125 B.1/25 C.25 D. 3125  #3What is the value of the expression 2/4^-3?Answers: A. 1/32 B. 1/6 C.128 D.256   #4  What value of k solves the equation? K^-2=1/64 Answers: A.1/8 B. 8 C. 32 D. 128  #5 What value of n solves the equation? 4^N= 1/64   Answers: A. –3   B. 3   C. 16   D. 256

Answer 1

$\#1\ \ \ 7^{-3}= \frac{1}{7^3} = \frac{1}{343}\ \ \ \Rightarrow\ \ \ Ans.\ C\\ \\ \#2\ \ \ \frac{1}{5^{-5}}=5^5=3125\ \ \ \Rightarrow\ \ \ \ Ans.\ D\\ \\ \#3\ \ \ \frac{2}{4^{-3}}=2\cdot4^{3}=2\cdot 64=128\ \ \ \Rightarrow\ \ \ Ans.\ C\\ \\\#4\ \ \ K^{-2}= \frac{1}{64} \ \ \Rightarrow\ \ \ \frac{1}{K^2} = \frac{1}{64}\\\\ .\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ K^2=64 \ \ \Rightarrow\ \ K=8\ \ \Rightarrow\ \ Ans.\ B$

$\#5\ \ \ 4^N= \frac{1}{64}\ \ \Rightarrow\ \ \ 4^N=4^{-3}\ \ \ \Rightarrow\ \ \ N=-3\ \ \ \Rightarrow\ \ \ Ans.\ A$

Answer 2

First question

The given expression is

$7^{-3}$

Which can also be written as

$\frac{1}{7^3}= \frac{1}{343}$

Therefore the correct option is C.

2.

The given expression is

$\frac{1}{5^{-5}}$

Which can also be written as

$5^5 = 3125$

So the correct option is D

3.

The given expression is

$\frac{2}{4^{-3}}$

Which can also be written as

$2*4^3 = 2* 64=128$

And the correct option is C

4.

The given equation is

$k^{-2} = \frac{1}{64} \\ k^2 = 64 \\ k^2 = 8^2 \\ k=8$

So the correct option is B

5.

The given equation is

$4^N = \frac{1}{64} \\ 4^N = 4^{-3} \\ N =-3$

And the correct option is A .