Suppose C and D represent two different school populations where C D and C and D must be greater than 0. Which of the following expressions is the largest? Explain why. Show all work necessary.

(C + D)^2
2(C + D)
C2 + D^2
C2 − D^2

Question

Suppose C and D represent two different school populations where C > D and C and D must be greater than 0. Which of the following expressions is the largest? Explain why. Show all work necessary.

(C + D)^2
2(C + D)
C2 + D^2
C2 − D^2

Eiwoh2 · Answer

@Shadow @dude 
I think the largest the third one, but I don't know how to prove it.

mhchen · Answer

Well you can compare them.
(C + D)^2 = C^2 + 2CD + D^2 
2(C + D) = 2C + 2D

Did you teacher tell you that C^2 is bigger than 2C?

Eiwoh2 · Answer

Well, i kinda figured that out with the fact that C^2 would be more equal than just C. Plus, the equation has a plus sign.

mhchen · Answer

Okay so like C^2 = C * C
                     2C = 2 * C

So if C is bigger than 2 then C^2 is bigger than 2C otherwise it's equal.
So we'll just say C^2 can be greater than 2C

Now it says C is bigger than D. So C^2 is bigger than D^2.

Out of all of them. Only the first equation has C^2 and D^2 while the rest only has D^2 or no exponents at all.

Understand?

Eiwoh2 · Answer

OH. So the first one would be the biggest, since it combines C and D and squares it...ok. I get it like that. XD