Help on Easy Slope Problems

Hello, this is my first post. I am trying to learn some easy algebra and was hoping to get some help.

I have some problems, and answers, but no idea how to arrive at the answers.

Please explain:

1) Find the slope of the following functions at X = 3

Q: Y = 4 + 3X^2

A: Slope = 18

Q: Y = 5X = 6X^3

A: 167

Q: Y = 6X

A: 6

For some reason the x^2 (x squared) is throwing me off. This is homework and answers from an old class, long time ago. Can't remember how to work it.

THANKS