What laws of exponent they are:

1. (x-²)-³ = x⁶
2. (a^m)^n = a^m^n
3. a⁰ = 0

The laws of exponents are:

a)  (x^n)*(x^m) = x^(n + m)

b)  (x^n)/(x^m) = x^(n - m)

c)  (x^n)^m = x^(n*m)

Now, let's see the given equations:

1) (x-²)-³ = x⁶   (true)

Here we se the third law, the "c"

(x^(-2))^(-3) = x^(-2*-3) = x^6

Then this equation is correct.

2)  (a^m)^n = a^m^n   (false)

This law does not exist, this is false.

An example of why this is false is:

Let's use the values:

a = 2, m = 1, and n = 2

then, in the left side we have:

(2^1)^2 = (2)^2 = 4

And in the right side we have:

2^(1^2) = 2^(1) = 2

We can see that we have different things in the left side than in the right side, then that relation is false.

3)  a⁰ = 0  (false)

Let's rewrite this as:

a^0 = a^(n - n)

Now we can use the second law to rewrite this as:

a^(n - n)  = (a^n)/(a^n)

And we have a number divided by the exact same number, we know that this is equal to 1, then:

(a^n)/(a^n) = 1

this means that:

a^0 = 1.

Then this is also false.

The only correct option is the first one.