七年级数学上册难题.pdf
2014 1 1.X1=1X2=3 _ X10=_ nxn=.2.1357 (1)17(2(320073.1Xx(2)200(3)2010.37 39 41 43 45 47 49 51 53 55 57 59 X3X42014 2 91 93 95 97 99 2 1 2 2 2 2 2 1.(a2)b05a b2a b(ab 2a b)4 2ab 2 2 2|*2 2.2(mn3m)m 5(mnm)+2mn.m1+(n+2)=0.3.mn=4 mn=12mn+2m+3n3mn+2n 2mm+4n+mn 21 23 25 27 29 2014 3 1.x961482242009 2x2y.3.a匕=旦型，贝U 3-3 a b 4.abcda cb dab=cdabcd=acbdadbc12pq=50V p=_ q=_ 5aba b=aa b=b3 2=33*2=2(2010%2009)(2007*2008)2014 4 1.m-n=3 5-2m 2n=_ 2._ 2a3b8189b 6a 232x2 3x784X2 6x 94._ ax5 bx3 cx 9x=1173 5x=-3mx-nx+15-5U x=36.x=2,ax3+bx+13,x=2,ax3+bx+1=2 2 21A=5x+4xB=3x+3C=8 A B+C.x=1 2014 5 2A 3x3 2x2 1B x3 2x2x 42A(A B)3.A=2a 2a B=5a1a=*3A 2B1(4)1.m=_ 3x2+2xy+y2 mx2x2 2 2 J 2 2 2ab3 a-2ab-b i-ia-mab-2b abU m=_ 32mx25x2 3x1(5x24y2 3x)x22m33m3(4m5)m3 2 3 2 4.xymx+3nxy 2x xy+y2m+3n 2014 6 5A=by2-ay-1 B=2y2 3ay-10y-12A-By2a2b a2b-1 3ab2 2,1-2abx 14ab3-2a2b2y-amb43 4 4m2xy 6x 2my 21m-2n=3(m-2n)2 2(m-2n)-1 25m3n=2（mn）4（2 mn）2 37a3-3(2a3b-a2b-a3)(6a3b-3a2b)-2(5a3-a)a x2014 7 1.-n2b.422._ 3a 4ba b32a b=5,6a3b 2 2 4.x=12ax+bx3x=2ax+bx2 1 2 2 52a b-a b ab3 6x=2ax3 bx 59x=2ax3 bx 57.abc8.2x23 3x5 2mn）2=_ 2014 8 93xm 5y2x3ynnm2014 9 1x2y3U 5 x2y2xayb3amb4a 2b 3c1 a2b22bcc2 53 x 102a2y63x217xy 9a 2b11032484 2014 10 12y3 3x2y2xy2 4x323x2y4x213x占3x+J x 6*4mnmn2(n1)5m2 2m 1U 2m24m2008 63(x1)24x x22(2x1)781012xx29abcdm5n2013 a+b-4cd+2mn=_ x2 O
