Question

What is the answer for these questions?

Answer 1

See below.

Explanation:

The negative exponent property is that
`a^(-x) = (1)/(a^x)`. Similarly, the zero exponent property is that
`a^0 = 1` for a ≠ 0.

Using these rules, we simplify the expressions in the problem as follows:

1.
`a^(-7) = (1)/(a^7)`

2.
`(21c^(18))^(-1) = (1)/(21c^(18))`

3.
`(3d^2)^0 = 1` if d ≠ 0

4.
`5(x^0)y^(-1) = (5)/(y)` if x ≠ 0