Monie3036354 Posted May 11, 2014 Report Share Posted May 11, 2014 It could be because it is late from where I am from, and I am just tired- but I am having problems simplifying this problem. Reply Link to post Share on other sites More sharing options...
Thrashmaster Posted May 11, 2014 Report Share Posted May 11, 2014 (edited) I can do the 10*31 part Hmm... Well, if you make the second quantity (the one in the parentheses) and multiply it by (both the top and bottom) by negative one, then you can combine it with the first quantity (the one with 10 as the numerator) and it'll rationalize the denominator. And then it gets easier from there. Edited May 11, 2014 by Thrashmaster Reply Link to post Share on other sites More sharing options...
Monie3036354 Posted May 11, 2014 Author Report Share Posted May 11, 2014 Thanks! Just seems hard to do without a calculator! Still don't really understand it but I think I am sleep deprived!! 1 Reply Link to post Share on other sites More sharing options...
Thrashmaster Posted May 11, 2014 Report Share Posted May 11, 2014 Thanks! Just seems hard to do without a calculator! Still don't really understand it but I think I am sleep deprived!!Ha ha, no problem. That would take a while to type into a calculator, but if they're allowed, I see no reason why it wouldn't work. Anyway, good luck! I assume you're studying for the final in a few days, right? 1 Reply Link to post Share on other sites More sharing options...
Rigel Posted May 11, 2014 Report Share Posted May 11, 2014 Realize that your expression can be rewritten as 210/2 - 1, which will be 31 (as we will have 25 = 32). Now, use the fact that (a + b)(a - b) = a2 - b2 to rearrange the expression at the bottom, by rewriting it as (sqrt(2) + 1)(sqrt(2) - 1) = 22/2 - 1 = 1, and then get 10*31. 1 Reply Link to post Share on other sites More sharing options...
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