(2ab^2)^-3÷(2a^2b^-1)^2

(a^2b-ab-a+1)/(ab^2+3ab-b-3)÷(a^2+a_2)/(b^2+b-6) ab^3+b^2+b-a+1 (ab(a^-2ab)-a^2b(a-3b))÷（3a^b） (a-b)^3+2ab(a-b) (a-b/ab)^2•(b-a/-a)^-3÷1/(a^2-b^2) 1/4a^2b^2{3ab(a+b)-5a(ab-b^2)}=? (a+b-2ab)(a+b-2)+(1-ab)^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=? a+b/2ab 2AB/A+B a+b/2ab ab/a+b=3 a-2ab+b/2a-3ab+2b? (-a^2b^2)÷(-ab^2)×(-3ab^3) (-a^2b^2)÷(-ab^2)*(-3ab^3) a^2-3ab+b^2/ab=( )/ab-3 a^2-3ab+b^2/ab=( )/ab -3 -3/4ab+2/3a^2b+ab-a^2b-1/2ab-5/3a^2b