Question Number 140445 by EnterUsername last updated on 07/May/21
$$\mathrm{If}\:\mathrm{the}\:\mathrm{straight}\:\mathrm{lines}\:\bar {{a}}_{{i}} {z}+{a}_{{i}} \bar {{z}}+{b}_{{i}} =\mathrm{0}\left({i}=\mathrm{1},\:\mathrm{2},\:\mathrm{3}\right),\:\mathrm{where} \\ $$$${b}_{{i}} \:\mathrm{are}\:\mathrm{real},\:\mathrm{are}\:\mathrm{concurrent},\:\mathrm{then}\:\Sigma{b}_{{i}} \left({a}_{\mathrm{2}} \bar {{a}}_{\mathrm{3}} −\bar {{a}}_{\mathrm{2}} {a}_{\mathrm{3}} \right)\:\mathrm{is} \\ $$$$\mathrm{equal}\:\mathrm{to}\:\_\_\_\_\_. \\ $$