I need help with these Algebra problems in which I need to give the square and the cube of each expression in simplified form.

1. -2t^2k
2. 3rs^4
3. 5m^3n
4. -4x^2y^2

just cube all the numbers and multiply the exponents by 3. For example

(-5xy^2)^2 = (-5)^2 (x)^2 (y2)^2 = 25x^2y^4

(-5xy^2)^3 = -125x^3y^6