how do you simplify exponents?

Question

for example here are some of the questions I got and I have no idea how to simplify

 

Simplify:

 

1. 10^-2

 

2. -3^-2

 

3. 1

    -

    3^-2

 

4. (-20)³

 

5. 2x² X 3x

 

could you show me how to do these questions? xx

Answer 1

Simplify:

1. 10-2 = (1/10^2) = 1/100=0.01

2. -3^-2= (1/(3^2))=(1/9)

 

3. (1/(3^-2) = 3² = 9

 

4. (-20)³ = -8000

 

5. 2x2 X 3x= 6X^3

 Exponents are subtracted if they are negative or are at the denominator and are added if they are multiplying.The sign will be negative if initially is negative and the power is odd. If the power is even the sign will be positive.