900-х=254+142                    a+325=124
                                             150+a+1000-540
d-254=452-121                     c+90=76+80
x-180=250+50

900-х=254+142900-х=396х=900-396х=504d-254=452-121    d-254=331d =331+254d=585x-180=250+50х-180=300х=300+180х=480a-325=124а=124+325а=449 150+a+1000-540=610+аc+90=76+80с+90=156с=156-90с=66