【1】ab+a-2ab-3a-b【2】3a²+5a-4a²-6a+2a²-3【3】10x²y-7xy²+4xy-9yx²-2xy【4】2xy²z-4xyz-3xzy²+2xyz【5】-4m²-2n²+3m²+2mn+n²【其中m=5n=4】【6】2x²y+3xy²-4yx²-6xy&#

a^2-3ab+b^2/ab=( )/ab-3 a^2-3ab+b^2/ab=( )/ab -3 ab^3+b^2+b-a+1 a^2b-ab+2ab^2-5a^b-4ab+3ab^2化简快 (a-b)^3+2ab(a-b) (-3ab)(a^2b-3ab^2+1) ab/a+b=3 a-2ab+b/2a-3ab+2b? (a^2b-ab-a+1)/(ab^2+3ab-b-3)÷(a^2+a_2)/(b^2+b-6) 已知a+b=A,ab=A+2008,1-2（a+ab）+（ab-2b）=3A.求a+b和ab的值 已知a+b=A ab=A+2008 1-2(a+ab)+(ab-2b)=3A 求a+b ab的值 已知a+b=A ab=A+2008 1-2(a+ab)+(ab-2b)=3A 求a+b ab的值 1/4a^2b^2{3ab(a+b)-5a(ab-b^2)}=? 1/a+1/b=3则a-ab+b/a+2ab+b值是? 如果a+b=3,ab=-1,那么(a+b)2-a-b+ab=? 3a²b-[2ab²-6(ab-1/2a²b)+4ab]-2ab -3/4ab+2/3a^2b+ab-a^2b-1/2ab-5/3a^2b 3(-2ab+3a)-(2a-b)+6ab 3(-ab+2a)-(3a-b)+2ab