Hello,

You're in the right way

(v^2/w^2) = a^2 - x^2

(v^2/w^2) - a^2 = x^2

-> this is false, it's (v^2/w^2) - a^2 = -x^2

So a^2 - (v^2/w^2) = x^2

Put it on the same denominator.

This will make :

(a²w²-v²)/w²=x²

So x=sqrt((a²w²-v²)/w²)=sqrt(a²w²-v²)/w

And sqrt is equivalent to ^(1/2)

I'm not sure my notations make sense... If necessary, i can make it easier to read