赞 0 踩已知3a=4b,则=a b分之a a-b分之b-a²-b²分之a²＝?-搜答案-百度作业网

|a|=3,所以a=3或-3,|b|=2,所以b=2或-2.因为ab＜0,所以a.b是异号的.有两种可能：1.a=3,b=-22.a=-3,b=2所以a-b=3-（-2）=5或-3-2=-5.不会的可

（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

则2a+2b+ab=2（a+b)+ab=2×3+6=6+6=12

(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

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

(a-b)*(3a+2b)=0b/a=-3/2a/b-b/a-(a*a+b*b)/ab=-2b/a=3

a+b=4两边平方a²+2ab+b²=16ab=2所以a²+b²=16-2ab=12所以3a²+3b²=3×12=36

(a+2)^2+|b+3|=0则：a+2=0,b+3=0得：a=-2,b=-3原式=3a²b-(2a²b-2ab+a²b-4a²)-ab=3a²b-3

3a²b+3ab²=3ab（a+b）=3×3×4=36

a+b>0,ab>0ab>0那么a,b同号又a+b>0,那么a,b同为正号即a>0且b>0∴3a+4b>0∴|3a+4b|=3a+4b即|3a+4b|=-3a-4b不成立①|a-b|+a-b=0则|a

-ab(a^2b^5-ab^3-b)=-a^3b^6+a^2b^4+ab^2=-(ab^2)^3+(ab^2)^2+ab^2=-(-3)^3+(-3)^2+(-3)=27+9-3=33

a²+b²+2a-4b+5=0a^2+2a+1+b^2-4b+4=0(a+1)^2+(b-2)^2=0则a+1=0b-2=0的a=-1,b=2则a²-2ab-3b

(-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

2（ab-3a)-3(2b-ab)=2ab-6a-6b+3ab=5ab-6(a+b)=5*(-5)-6*(-4)=-25+24=-1

ab+ba=a2+b2ab=(a+b)2−2abab，∵a+b=3，ab=1，∴(a+b)2−2abab=9-2=7，故答案为7．

(a²b²+2ab+1)+(a²+2ab+b²)=0(ab+1)²+(a+b)²=0所以ab+1=a+b=0ab=-1,a+b=0所以a=1

2(ab-3a)-3(2b-ab)=2ab-6a-6b+3ab=5ab-6(a+b)=3×2-6×4=-18

a-b-3ab=0a-b=3ab(2a+3ab-2b)/(a-ab-b)=[2(a-b)+3ab]/(a-b-ab)=9ab/2ab=9/2

可以这么算a-b=1ab=23a+ab-3b=3(a-b)+2=3×1+2=5

|-a|-a=0,则a是非负数；|ab|/ab=-1（