先化简,再求值:(2a b)(a-2b) 2b²,其中a=根号2,b=根号2 2
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2a√(3ab³)-b/6*√(27a³b³)+2ab√(3ab/4)=2ab√(3ab)-a²b/2*√(3ab)+ab√(3ab)=3ab√(3ab)-a&
a,b满足|a+√3|+√b-2{根号(b-2)}=0a+√3=0b-2=0a=-√3b=22(a平方b-ab)-3(a平方b-三分之二ab)=2a^2b-2ab-3a^2b+2ab=-a^2b=-(
∵a2+ab-2b2=0∴(a+2b)(a-b)=0∴a=-2b或者a=b原式=(a²-b²-a²-b²)/ab=-2b²/ab=-2b/a当a=-2
解[(a+b)²/a-[a-(2ab-b²)/a]=(a+b)²/a-[(a²-2ab+b²)/a]=(a²+2ab+b²)/a-
[a/(a+b)-b/(b-a)-2ab/(a^2-b^2)]/(1/a-1/b)=[a(a-b)+b(a+b)-2ab]/(a^2-b^2)/[(b-a)/(ab)]=[a^2-ab+ab+b^2-
原式=(a−2a(a+2)-a−1(a+2)2)•a+2a−4 =a2−4−a2+aa(a+2)2•a+2a−4 =1a2+2a.由a2+2a-1=0,得a2+2a=1,∴原式=1
当a=1,b=-1时3ab-2{a²-ab]-[a²-ab]=3ab-(a²-ab)=4ab-a²=4×1×(-1)-(1)²=-4-1=-5
(a/ab-b^2-b/a^2-ab)/(1+a^2+b^2/2ab),其中a=-2,b=1=[a/b(a-b)-b/a(a-b)]/[(2ab+a²+b²)/2ab]=[(a
补充:[(a)-(《2ab-b^2》]/a通分得(a^2-2ab+b^2)/a〔[(a^2-b^2)/a〕/[(a-(2ab-b^2)/a]=〔[(a^2-b^2)/a〕/{[(a^2-(2ab-b^
2a²+3ab+b²-a²-ab-2b²=2a²-a²-2b²+b²+3ab-ab=a²-b²+2a
-1/3(3a²-6ab)+[a²-1/2(2a+2ab)]=-a²+2ab+a²-a-ab=ab-a=-1/2a-a=-3/2a你哪里抄错了吧手机提问者在客户
(a²-b²)/(a²-ab)÷(a²+2ab+b²)/a=[(a+b)(a-b)]/[a(a-b)]÷(a+b)²/a=(a+b)/a×a
(1/ab)(a+b-4/(a+b))ab=15a-b=2(a-b)^2=4(a+b)^2=(a-b)^2+4ab=64a+b=8(ab=15>0,a-b=2>0所以a+b>0)(1/ab)(a+b-
原式=[a-2a(a+2)-a-1(a+2)2]•a+2a-4=a2-4-a2+aa(a+2)2•a+2a-4=a-4a(a+2)2•a+2a-4=1a(a+2).当a=2-1时,原式=1(2-1)(
(a²+ab-ac)/(a²-ab)·[(a-b)²-c²]/(a²+2ab+b²)÷[a²-(b-c)²]/(b&su
/>化简:原式=3ab-2(a²-ab)-(a²-ab)=3ab-2a²+2ab-a²+ab=-3a²+6ab求值:原式=-3a²+6ab=
(a-2b)(a+2b)+ab3÷(-ab),=a2-4b2-b2,=a2-5b2,当a=2,b=-1时,原式=(2)2-5×(-1)2=2-5=-3.
原式=-(9a^4-18a^3+3b^2+4a^3b)=-(9a^4-14a^3b+3b^2)=-(9*1-14*(-1)^3*(-2)+3*(-2)^2)=-(9-28+12)=7
原式=2a^2b+2ab^2-2ab^2+1-a^2b-2=2a^2b-a^2b+2ab^2-2ab^2-1=a^2b-1
-a²b+(3ab²-a²b)-2(2ab²-a²b)=-a²b+3ab²-a²b-4ab²+2a²