I have been reading a book about radio electronics because I am interested in the topic. I got stuck on part about impedance mathcing, author draw a circuit with source resistance and some load resistance, the point was to match these resistances so that power output on the load is maximized without using transformer, hence only using RLC elements, he/she first added one element parallel to the load and wrote equation for combined impedance, I am very confused about it because it seems like souce resistance is in parallel with this newly added impedance, how so? Second element seems to be added in a series and is simple to understand as it only just compensates for imaginary part of impedance from the equation. I don't uderstand how author got the first equation if anyone knows whats up please help UwU