Powerprep problems

[socratessa]

Hello everyone:

I am stuck with these two problems (enlosed) and I believe many of you will find them easy. Help!

Another thing ... how can I cut and paste, say a snapshot from PP, on this page so I don't need to attach a file?

Thanks for your help.

[bscout]

You have to substitute the values and do the operation as are indicate in the equation.

1) x○x=x^2+x^2-x^2==>x○x=x^2 True.
2) x○y= True (easy one).
3) x○1= x^2+1^2-x≠x False.
4) x○0=x^2+0+0*x=x^2 True.
5) True.



Column A:
1/[(1/x)+(1/y)]=xy/(x+y)

Column B:
(1/x)+(1/y)=x+y/(xy)

If x=2 and y=2 both columns are equal and the answer is C. But if x=2 and y=3 the first column is 6/5 and the second is 5/6, the answer in this particular cas is A. We need more data to infer a definitive conclusion. Answer D.

Hope is clear.

[socratessa]

bscout, thanks so much! Yes, it's very clear. BTW, how do you "cut and paste" on the message body of this post like you did? I tried many times, it does not show!

[Megamind]

1st one C


2nd

let x = y =2, both are equal

x= 2 y =3, then A is bigger, so D