That '70s Show, Season 3

Eric:
So, looks like I'm gonna spend the weekend with Kelso, tutor him in math.

Red:
Really.

Kitty:
Hmmm.

Red:
So, you're allegedly tutoring Kelso in math?

Eric:
Yes sir.

Kitty:
Are you good in math?

Red:
What's the square root of x?

Eric:
Um, I really can't answer that?

Red:
A-HA!

Eric:
No, see. X is a variable so until you define its parimeter is the only possible answer is the variable or x if you prefer.

Red:
Is that right?

Kitty:
Sounds good. Will Michael's parents be home?

Eric:
Yes.

Red:
Are they as dumb as he is?

Eric:
I can't lie. Yes. Yes, they are.

Red:
Right answer. (to Kitty) That was a trick question. I know they're dumb

Eric:
So, I can go?

Red:
You can go, but I'll be watching the news. And if anything gets vandalized, or explodes, or catches on fire, X is gonna equal me kicking your ass.