Power of a Real numbers with positive and negative exponent

Express as a power of a rational number with negative exponent. (((-3)/2)^(-2))^(-3)

Express as a power of a rational number with negative exponent. (2^(5)-:2^(8))xx2^(-7)

Express each of the following as power of a rational number with positive exponent : (1/4)^(-3) (ii) 5^(-3)\ x\ 5^(-6) (c) ((-1)/4)^(-5)x\ ((-1)/4)^(-7)

negative integral exponent

What is meant by power of a lens ? When is it positive or negative? Define one dioptre.

What are rational numbers? Give Examples of five positive and five negative rational numbers. Is there any rational number which is neither positive nor negative? Name it.