若a*3-b*3=3a*2b+3ab*2+1 则a-b=?

(a-b)^3+2ab(a-b) ab/a+b=3 a-2ab+b/2a-3ab+2b? 若a/b+b/a=3,求a^2+ab+b^2/a^2-ab+b^2的值 a^3-ab^2 =a （a^2 -b^2) =a(a+b)(a-b) 已知3a*a+ab-2b*b=0(a不等于0,b不等于0),求a/b-b/a-(a*a+b*b)/ab的值. 若ab不等于0,且3a=b,求代数式b/3a-(-b)/a-a/2b/(-b) b/a+a/b=3,求2ab/(a*a+b*b)-(3a*a+ab+3b*b)/2ab的值 若a+b=3 ab=-2,求a+ab+ab+b的值 已知a*a-ab=3,ab+b*b=-5,求代数式a*a+b*b与a*a-2ab-b*b的值 若a+b-ab=0,则(3a+3b-ab)/(2a+2b+ab)= 若a+b=3,ab=-2,求(5a-5b-ab)-(4a-6b-3ab) 若a-b=3ab,则2a-ab-2b/a+2ab-b=? 若a-b=3ab,求2a-ab-2b除以a+2ab-b的值 若a-b=4,ab=1,求(-2ab+2a+3b)-(3ab+2b-2a)-(a+4b+ab)的值 若a-b=4 ab=1 求（-2ab+2a+3b)-(3ab+2b-2a)-(a+4b+ab)的值 若a-b=4 ab=1 求（-2ab+2a+3b)-(3ab+2b-2a)-(a+4b+ab)的值 1/4a^2b^2{3ab(a+b)-5a(ab-b^2)}=? 如果a+b=3,ab=-1,那么(a+b)2-a-b+ab=?