Here's a little math problem. Let's see if you can actually solve it. While I know the solution, I have no idea how to reach it by calculation (I guessed ). a = c2d + c2 b = cd + a:b c = a - b - cd d = ((c+c+c):c):c Figure out the values of a, b, c and d. Only one solution is possible. And just to clarify ":" means to divide. EDIT: Holy crap, wrong forum. >_

Then why the hell did you bother posting? Anyways, I would imagine you would have to put answers in terms of other words. e.g c+c+c=3c, 3c:c = 3, 3:c=d and just workd your way up by just putting stuff in terms of others.

This is not my homework, I made the equations ... Just modified one that I was able to solve and added a twist ... Warning: Spoilers inside! The solutions are a = 10, b = 5, c = 2, d = 1,5. I'm just trying to figure out the calculation method. And please, can a mod move this to another forum?

For the calculation, just replace the variables with equivalents. since d = *long equation here* just plug it into a so you have two variables etc im too lazy

a = c^2d + c^2 b = cd + a/b c = a - b - cd d = ((c+c+c)/c)/c d = 3/c substitute d = 3/c a = 3c + c^2 (1) b = 3+ a/b -> b^2 = 3b + a, a = b^2 - 3b (2) c = a - b - 3 (3) combine (1) and (2) 3c + c^2 = b^2 - 3b (4) substitute (2) into (3) c = b^2 - 3b - b - 3 = b^2 - 4b - 3 (5) substitute (5) into (4) (b^2 - 4b - 3)*(b^2 - 4b) = b^2 - 3b You get b(b^3 - 8b^2 + 12b + 15) = 0, so if b = 0, then c^2d + c^2 = c^2d, so c =0, then d = 0/0 which isn't desirable so b=/=0 That means b^3 - 8b^2 + 12b + 15 = 0 because 15 has factors of 1,3,5,15, try factoring with (b-1), doesn't work. (b-3) doesn't work, Factor with (b-5) you get (b-5)(b^2-3b-3) = 0 so if b = 5, then c = 25-20-3 = 2 from (5), then a = 3*2 + 2^2 = 10 from (1), and d = 3/2. (The only way to factor out b^2 - 3b - 3 is factoring by (b-1) and (b-3), and we've already done that 3 lines above and failed) The reason you factor with (b-x) where x is a factor of 15 is because the only way you get 15 at the end is by multiplying (b-x) by some other constant (For example, from (b^2 - 3b - 3), 15 has to be -x * -3 otherwise you get a multiple of "b", not a constant) Before university, there may be one acceptable solution but I see a=0, b=0, c=0, d=0/0 as an answer too.

Code got busted there, should have casted to double or float, because mathematically 1 != ((3 * 2) / 2) / 2. edit: tried bolding the code, didn't work =P

yeah, my bad, what a stupid mistake. This is what working in scripting languages does to a person, you start taking these small things for granted

I also would like to contribute to this wonderful thread: - Find the volume of the solid generated by revolving the plane region bounded by the equations : y=(1+x^2)^-(1/2) ; y=0; x=1; x=-1 Revolved around X-axis, using the disc method.