.5 = (X + Y) / (X + 2*Y)

I'm trying to find the equation for X or Y so I can put it into my physics formula but I've straight up blanked on how to do algebraic division.

What would X or Y =?

I keep coming up with
.5 * (X + 2Y) === .5X + Y = X + Y, === .5X - X = Y - Y === .5 = Nothing..

What am I doing wrong? or is this formula not possible to find out X or Y

Thanks!

.5x - x isn't .5, it's -.5x

Right, I just did that quick. The main problem is, I'm still getting X to equal nothing, which doesn't give me an equation to insert into the other problem with X and Y variables.

originally you indicated 0.5 = 0 and your variables disappeared, which is a problem. but now that it's corrected, it's easy to see x is not equal to nothing; x is equal to 0. i think the only solution to that equation is {x = 0, y = 1}. that should simplify your work, i think?

-.5x = 0
x = 0

which is very different from:
0.5 = 0

x = 0 is pretty clear if you look at the equation:

X + Y
______
X + 2*Y

notice how you're adding x to both the numerator and denominator? to make it equal to 0.5 means the bottom must be double the top. considering that the only difference between the bottom and top is an extra Y on the bottom, how do you plan on making that double? with y = 1 and x = 0

you were trying to establish a relationship between x and y. meaning given x, find a suitable y to make it true, an vice versa. it simply cannot exist for a general x and y, and it's clear when you look at it.

eg, set y to 0. then you get: x / x = 0.5
which is clearly never going to happen.

This post was edited by carteblanche on Oct 1 2014 06:36pm