Please explain to me how to do these?!?

Question

I know I've just asked questions about Algebra, but please help me!
Please explain to me how to do these types of problems. Honestly, I'm so confused.

1. (-2xy)^4 (-x^2)
This problem needs simplified.

2. (3/7)^-1

3. (3/x)^4

Once again, I'm very confused! Help would ve greatly appreciated!!! :)

Answer 1

1. (-2xy)^4 (-x^2)
This problem needs simplified.

(-2xy)^4(-x^2)

(-2^4)((x^4)(y^4)(-x^2)                                                   (ab)^m=(a^m)(b^m)

(16)(x^4)(y^4)(-x^2)                                                      -2x-2x-2x-2=16

-16(x^6)(y^4)                                                               (x^n).(x^m)=(x^(n+m))

        there fore        -16(x^6)(y^4)

Answer 2

3. (3/x)^4

(3/x)^4

(3^4)/(x^4)                                        (a/b)^m=(a^m)/(b^m)

81(x^4)

there fore      (3/x)^4=81(x^4)

Comments

(3/x)^4 = 81/(x^4)

Answer 3

2). (3/7)^-1

The Rules of exponentiation is : x ^-p = 1/ x^p and 1/[a/b] = b/a

= 1/[3/7]

= 7/3.