已知|2a b-4| (4a-b-2)

（2a+3b-2ab)-(a+4b+ab)-(3ab+2b-2a)=3a-3b-6ab=3(a-b)-6ab=3*2-6*(-3)=6+18=24

原式=3a^2+4ab-a^2-2a^2-4ab+2b^2=2b^2所以该代数式的值与a的值无关,当b=2时,代数式2b^2=2*2^2=8

ab+a=-2,ab+b=-10两等式相减,得：a-b=8-2a-{-4b-3[(ab+a)²-a]}-1/2[(ab+b)²-2b]=-2a-{-4b-3[(-2)²-

(-2ab+2a+3b)-(3ab+2b-2a)-(a+4b+ab)=-2ab+2a+3b-3ab-2b+2a-a-4b-ab=(-2ab-3ab-ab)+(2a+2a-a)+(3b-2b-4b)=-

2a+3ab+2b=2a+2b+3ab=2(a+b)+3ab=2*4+3*1=11a³-a²b+a²b²+a²b-a²b²+b&#

a为2,b为-4,结果为4

（3a-4b-ab)-(a-2b+3ab)=3a-4b-ab-a+2b-3ab=2a-2b-4ab=2（a-b）-4ab=2×（-1）-4×（-2）（将a-b=-1,ab=-2代入）=-2+8=6

(2a+3b-2ab)-(a+4b+ab)-(3ab+2b-2a)=2a+3b-2ab-a-4b-ab-3ab-2b+2a=3a-3b-6ab=3(a-b)-6ab已知a-b=3,ab=-33(a-b

原式=5a²b(a-b)-3ab(a-b)²-5ab²(a-b)=ab(a-b)[5a-3(a-b)-5b]=ab(a-b)(5a-3a+3b-5b)=ab(a-b)(2

a-3ab+b/2a+2b-7ab分子分母同除以ab=(a/ab-3ab/ab+b/ab)/(2a/ab+2b/ab-7ab/ab)=(1/b-3+1/a)+(2/b+2/a-7)=[(1/a+1/b

因为|a-4|+(b-9)^2=0,所以|a-4|=0,(b-9)^2=0,即a=4,b=9所以a^2+ab/b^2*a-ab/a^2-b^2=a（a+b）a(a-b)/[b²（a-b）（a

通分.b-a=4ab.原式=-[ab-2(b-a)]/[2ab+(b-a)]=-7/6

1/a+1/b=7(a+b)/ab=7a+b=7ab原式=[(a+b)-4ab]/[2(a+b)-3ab]=(7ab-4ab)/(2×7ab-3ab)=3ab/11ab=3/11

a-b=3,ab=-2（2a+3b-2ab)-(a+4b+ab)-(3ab+2b-2a)=2a+3b-2ab-a-4b-ab-3ab-2b+2a=3a-3b-6ab=3*3-6*(-2)=21

(-a-4b-ab)-(2ab-2a-3b)-(3ab+2b-2a)=-a-4b-ab-2ab+2a+3b-3ab-2b+2a=3a-3b-6ab=3(a-b)-6ab=9+18=27

（22a+3b-2ab)-(a+4b+ab)-(3ab+2b-2a)=22a+3b-2ab-a-4b-ab-3ab-2b+2a=23a-3b-5ab题目抄差了!（22a+3b-2ab)应该是（2a+3

1、B-A=4abA=a²-2ab+b²那么B+A=4ab+2A=4ab+2(a²-2ab+b²)=2a²+2b²2、A=a²-2

由a-b=4,ab=-1解得b=-2+3^0.5或-2-3^0.5故有(-2ab+2a+3b)-(a-4b+b)=-2ab+a+6b=-2*(-1)+a-b+7b=2+4+7b=6+7b=6+7（-2

(2a+5b-3ab)-(a+6b-ab)-(2ab+2b-2a)=2a+5b-3ab-a-6b+ab-2ab-2b+2a=3a-3b-4ab=3(a-b)-4ab=12-12=0

原式=2a+3b-2ab-a-4b-ab-3ab-2b+2a=3a-3b-6ab=3(a-b)-6ab=3*3-6*1=3