x+11/43=9/12 21/34-y=16/51 21/78-a=4/39 x+36/155=45/62 77/89+y=173/178 19/21-a=14/210

х=9/12-11/43 х=387/516 -132/516 = 255/516=85/172 ; у=21/34-16/51=63/102-32/102=31/102; а=21/78-4/39=21/78-8/78=13/78 =1/6; х=45/62-36/155=225/310-72/310=153/310; у=173/178-77/89=346/356-308/356=38/356 =19/178; а=19/21-14/210=380/420-28/420 =352/420=88/105