# Algebra Question **URL:** \ **Category:** Factual Questions\ **Created:** [September 21, 2003, 3:15pm UTC](https://boards.straightdope.com/t/algebra-question/202974 "2003-09-21T15:15:57Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![thwartme](https://avatars.discourse-cdn.com/v4/letter/t/ecc23a/32.png) [@thwartme](https://boards.straightdope.com/u/thwartme)\ **Post date:** [September 21, 2003, 3:15pm UTC](https://boards.straightdope.com/t/algebra-question/202974/1 "2003-09-21T15:15:57Z")
Hey gang, A little help for the mathematically challenged, if you’d be so kind. In the equation: (x-y)/x = 0.35 How could I solve for x? Thanks, Thwartme ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [September 21, 2003, 3:22pm UTC](https://boards.straightdope.com/t/algebra-question/202974/2 "2003-09-21T15:22:02Z")
(x-y)/x=.35 x-y=.35x -y=.35x-x -y=x(.35-1) x=-y/.65 That should be your answer, some of the lines could be formatted differently, but in the end you should get a similar(well, the same) answer. ---
**Author:** ![Absolute](https://avatars.discourse-cdn.com/v4/letter/a/b2d939/32.png) [@Absolute](https://boards.straightdope.com/u/Absolute)\ **Post date:** [September 21, 2003, 3:23pm UTC](https://boards.straightdope.com/t/algebra-question/202974/3 "2003-09-21T15:23:14Z")
(x-y)/x = .35 x-y = .35x : multiply by x -y = .35x -x : subtract x y = x - .35x : invert signs y = x (1 - .35) : factor out x x = y / .65 : divide ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [September 21, 2003, 3:23pm UTC](https://boards.straightdope.com/t/algebra-question/202974/4 "2003-09-21T15:23:17Z")
WAIT, missed a negative sign. This is the correct answer. (x-y)/x=.35 x-y=.35x -y=.35x-x -y=x(.35-1) x=-y/-.65 x=y/.65 ---
**Author:** ![thwartme](https://avatars.discourse-cdn.com/v4/letter/t/ecc23a/32.png) [@thwartme](https://boards.straightdope.com/u/thwartme)\ **Post date:** [September 21, 2003, 3:25pm UTC](https://boards.straightdope.com/t/algebra-question/202974/5 "2003-09-21T15:25:24Z")
Man, that was fast! You folks rock! ---
**Author:** ![C\_K\_Dexter\_Haven](https://avatars.discourse-cdn.com/v4/letter/c/b2d939/32.png) [@C\_K\_Dexter\_Haven](https://boards.straightdope.com/u/C_K_Dexter_Haven)\ **Post date:** [September 21, 2003, 3:44pm UTC](https://boards.straightdope.com/t/algebra-question/202974/6 "2003-09-21T15:44:22Z")
And, as a footnote, multiplying both sides of the equation by x requires the assumption that x =/ 0 How come we’re doing your homework? ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [September 21, 2003, 4:09pm UTC](https://boards.straightdope.com/t/algebra-question/202974/7 "2003-09-21T16:09:51Z")
> [@](#): > > \*Originally posted by C K Dexter Haven \* > \*\*And, as a footnote, multiplying both sides of the equation by x requires the assumption that x =/ 0 > > How come we’re doing your homework? \*\* That wouldn’t be a requirement of multiplication would it? As presented to us, X can’t be zero since it’s already on the bottom. [sub]BTW Dexter, I just saw The Philidelphia Story, I always wondered what your name meant[/sub] ---
**Author:** ![Achernar](https://avatars.discourse-cdn.com/v4/letter/a/e274bd/32.png) [@Achernar](https://boards.straightdope.com/u/Achernar)\ **Post date:** [September 21, 2003, 4:52pm UTC](https://boards.straightdope.com/t/algebra-question/202974/8 "2003-09-21T16:52:08Z")
The thing is, (x, y) = (0, 0) is not a solution to the original equation, even though the form x = y / 0.65 would make you think it is.