i don't understand this math concept

Question

Write this expression with a positive exponent and then simplify.

(4u)^-1

Answer 1

(4u)^-1  =   1/(4u)

Answer 2

(4u)^(-1)=1/4u

raising a number to the -1 power gives you the reciprocal of the number

a^(-1)=1/a

 

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

 

(1/7)^(-1)=7/1=7