(a+b)^2-3ab=(a^2+b^2-ab),等号右边的怎么化简为等号右边的

ab/a+b=3 a-2ab+b/2a-3ab+2b? (a-b)^3+2ab(a-b) 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. b/a+a/b=3,求2ab/(a*a+b*b)-(3a*a+ab+3b*b)/2ab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 a/b=2 ,(a*a-ab+b*b)/(a*a+b*b)= 若a/b=2 则a*a-ab+b*b/a*a+b*b等于? 如果a/b=2则a*a-ab+b*b/a*a+b*b求值 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=? ab=-2 a+b=3 求ab(a²+b²)-a-b 1/a+1/b=3则a-ab+b/a+2ab+b值是? a+b/2ab 2AB/A+B a+b/2ab a*b=a+b-2ab (3*2)*1 a^3-a^B-aB^2+B^3=0