-b^2+14ab+A=7a^2+4ab-2b^2,则A=
若a/b=2 则a*a-ab+b*b/a*a+b*b等于?
如a-b=4,ab=1,则(2-ab+2a+5b)-(3ab+2b-2a)-(3a+4b-ab)=
1/a-1/b=4,则[a-2ab-b]/[2a-2b+7ab]=
已知1/a+1/b=4则a-3ab+b/2a+2b-7ab=?
a+b/2ab
2AB/A+B
已知:|a|=2,|b|=4,a>b,ab
a^2-3ab+b^2/ab=( )/ab-3
a^2-3ab+b^2/ab=( )/ab -3
已知a+2b=0,求a*a+2ab-b*b/2a*a+ab+b*b
若a/b=2,求分式a*a+ab-b*b/a*a-2ab+2b*b
先化简,再求值;(a+b)/ab-4/(ab^2+a^2b),其中ab=15,a-b=2