Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

$x = 1825 + \large \frac{91}{1217}$

$y = 7 + \frac{2}{3}$

$z = 1827 + \frac{2}{3}$

Is there any way to turn $x$ into $z$ only using the first two terms, and/or a constant, and the operators '$+$','$-$','$*$','$/$'.

I know I can take $((x)-(x \mod 10)) + y = z$, but this uses a modulus.

... Basically the core of the question is can I change any number's last digit and its decimal value to something I decide by only using the number itself and the desired digit and decimal?

... I feel like splitting the numerator and denominator and running independent operations on each might be the way to go.

share|improve this question
4  
You say you're allowed to use a constant, so why don't you just calculate $z-x$ and then add that constant to $x$? –  Gerry Myerson Feb 9 '13 at 11:50
    
I'm sorry, I misspoke in the question... you can only use the first two terms and a constant. –  Peregrine Feb 9 '13 at 11:55
1  
@Perry: That doesn't answer Gerry's objection at all. –  Chris Eagle Feb 9 '13 at 12:53
    
Gerry uses the z term. $z-x$. The problem, though I mispoke it before Gerry's suggestion, states you can only use the terms x and y and a possible constant. –  Peregrine Feb 9 '13 at 12:58
add comment

1 Answer

$z=x+y-5\frac{91}{1217}{}{}{}{}{}$

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.