I'm looking for the solution to a practical maths problem that is way beyond my level of competence

I'm not sure if this is the appropriate site to pose this, and if its not I'm open to suggestions of sites where I could directed it.

The problem below I thought at first this would be a fairly simple, but it turns out to be a lot more complicated than I first imagined. I was good at maths at school, but that was 20 years ago and after attempting this I've realized it is beyond my scope..

I have 3 known inputs, LongStdDev, ShortStdev and MarketStdev. And I have two targeted inputs, PortfolioBeta and PortfolioStdev.

I only have two variables, LongWeight and ShortWeight.

PortfolioBeta = LongWeight - ShortWeight
PortfolioStdev = Sqrt((LongWeight*LongStdev)^2 + (ShortWeight*ShortStdev)^2 +
(abs(LongWeight-ShortWeight)*MarketStdev…

From these two formulas and five inputs is it possible to calculate the LongWeight (and by Inference the ShortWeight)? Trying to use what I remember from high school maths I hit a wall when I try to substitute {PortfolioBeta-LongWeight} for {ShortWeight} and then square it.

PortfolioBeta = LongWeight - ShortWeight

LongWeight = beta - short weight

PortfolioStdev = Sqrt(((beta - short weight)*LongStdev)^2 + (ShortWeight*ShortStdev)^2 +
(abs(beta)*MarketStdev)

now you have a formula with only one variable!
square both sides, plug the numbers that you know,

you will eventually get to:

A ShortWeight^2 + B SortWeigth + C = 0

Jam that into the quadratic formula Sw = ( -B +- sqrt(B^2 - 4AC))/2A