Pick one of the variables. In this case, it doesn't really matter which. Solve one of your equations for the chosen variable in terms of the other variable. Take the expression in the non-chosen variable that is now equal to the chosen variable and substitute that expression in place of the chosen variable in the other equation. Solve the single variable equation that results. Once you have a value for one of the variables, substitute that value into either of the equations and solve the resulting single variable equation for the remaining variable.
John
Egw to Beta kai to Sigma
My calculator said it, I believe it, that settles it