- #1

silvermane

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## Homework Statement

a.) Prove that if a+b[tex]\sqrt{2}[/tex] = c+d[tex]\sqrt{2}[/tex] with a,b,c,d all in Q, then

a = c and b = d.

b.) Prove that a^2 - 2b^2 with a, b in Q is nonzero unless a=b=0

## The Attempt at a Solution

I really don't know where to start. Any tips would be nice. I just need to see something that I'm not seeing at the moment. :(

I don't need an answer, just a little jolt lol. It will be greatly appreciated! :)