General

@iDawnStrike: @DriveXIII: @Snovvy: Yeah, I acknowledged my oversight a bit earlier. Stupid mistake, haha. Thanks for offering help. I'm set.

@razormana: @qtprincessxoxo: Perfect. Thanks to you both again.

@AfroLeader:
So it goes from (-2)^-4 to 1/(-2)^4 right.
then you expand the bracket.
1/(-2)^4x^4
=1/16x^4

^Got it. Tyvm!

[quote=razormana]@AfroLeader
[/quote]

About the exponents:

http://i.imgur.com/HKiLk.jpg

It says the answer is D. How do you get from your answer to D?

No, it's D.
Since 'a' the radius = 10m, the diameter is 20m.
Since the sides of the square is 20m, the area of the entire square is 400m^2.
Now we want to find out the black area of the figure, so all you do is subtract the entire area of the square with the white circle within;
Area of circle is pi*r^2, and since this problem says pi = 3, that makes it 3*(10m^2) = 300m^2
400m^2 - 300m^2 = 100m^2. Your teacher is right.

[quote=qtprincessxoxo]diameter is 20

20^2 = 400
3*100 = 300
400-300 = 100

D)[/quote]

But isn't the area of a circle pi * r^2? It'd be 3 * 10^2 = 3*100 = 300, no?

[b]Edit:[/b] @razormana: Missed that. Thanks.

@AfroLeader

Read the question again, its asking for the shaded area which is the portion of the square that thee circle doesn't cover.
@qtprincessxoxo has the right working for it.

(-2x)^-4 in positive exponents?
1/(-2x)^4
a negative exponent is the same as doing the reciprocal with the power becoming positive.