12ab5ab4x2y31yx28302.521232xyzxy0.523yx732yx1-5x3y2_______________3Ayx2323xyBxy3yx2Cx222xDxy5yz5k13xkyx2y235kxy439yx2myx35219yxnm=_________,n=___________12312+3412a2b3a2b0.5a2b23322332923abababab233223322325xyxyxyxy1x222542xxkxx2xk=;2x,y222291063xkyxyxy2yk=;1222342565xxxxx112x2.222451aaaa2a1213(2)bc=2(23)xc=33(2)xy=4(2)xy=52(23)(46)xyxy=63(42)xy=(126)xy=73(32)xy==-118a+2b+5ab2222(53)3(2)abab3a2a3ab14x3y2y2x2x32y33x2y3x33y37x2y33a25a+421a3+2a2+443x27x22x23x2x1221Ax,223xB(1)AB2;(2)32AB;22x2x13x2A2253xx237xx1A?23xzyzxy235xzyzxy235xzyzxy46212222923532xyxyxy31,1yx)4(2)3(22xxxx2x1.222515,1,32,,,1xxxxxxA.3B.4C.5D.62.A2233xxB235325aaaC33xxD10.2504abab3.2y32x32mxy4m24A.20B.20C.28D.284.A11(3)322xyxyB()mnabmnabC1(463)2332xyxyD112112()()237237abcabc5.,2,3dcba)()(dacb()A1B1C5D15632281xxx323253xmxxmA2B2C4D47.6x12y12325x2y5xy7x4x2y5xy7xA.1412B.1412C.1412D.141213222112,3,1,,,,4,,43xyxxymnxabxx________.230___.30_________.423mab4112nab==.532131512328562x23y786x29y8_____.7.an=________________n.11b7a6b3a52)24()215(2222abbaabba3)5(3)8(2222xyyxyxxy4]2235[)213(2xxxxx5222226284526xyxyxyxxyyxxy1234n471013an222213(21)(),1,2.22xyxyxyxyxy14622112()822aabaabab72,23),3123()3141(222yxyxyxx82.325Axx2116Bxx1A2B21xA5B.3.ab=3,a+b=43ab[2a-(2ab-2b)+3].4.xP3x26x7Qax2bxcPQPQabcPQ(3x26x7)(ax2bxc)(3a)x2(b6)x(7c).(1)a_________PQ(2)a_________b__________PQ(3)a_________b__________PQ(4)a_________b__________c__________PQ5.abc253220ab2113abcxy722222234abababcacabacabc6.13235122abbaabba253abab23a4b17c222278(2)abcacbbcaababc.333mnab33ab229Amxxyy223Bxnxyy232ABABA4a4b222223224abababaaab7.4323axbxcxdx2x202x162x423axcx8.122253Axxyy22234Bxxyy230ABCC22347Axyxyx233Bxyxyx3ABxy3AB.32351ABxx2235ACxx.2xBC.4323951Aabb233782Babb.2AB3BA9.xyyx22yx34yx48yx51619.2n10.*abbaba2)214(311.3.-3a,b,c;5.12.1223.123n(3)(2)(1)13,,r,a,b.(1);(2)500,200,20,().14.24cmacm23cm31.1;2cma4cma7.()12ABCDabABbLS