Hi,

is someone of you using some equation editor SW (free) and can recommend some?

The perfect one should know to extract variable/solve equation/system of equations. Just good one can help with modifications.

Example:

V_{x} + a * v_{x} = X_{x} + b * v’_{x}

V_{y} + a * v_{y} = X_{y} + b * v’_{y}

I’d like something, that helps me to derive formula for a

a = (X_{x} + b * v’_{x} - V_{x}) / v_{x}

and additionaly use (substitute) that in second equation to find formula for b…

If you recommend something, would be good to add some instructions how to achieve that